CVE-2026-6104 (GCVE-0-2026-6104)
Vulnerability from cvelistv5 – Published: 2026-05-10 04:35 – Updated: 2026-06-30 12:11
VLAI?
Title
Global buffer over-read in mb_convert_encoding() with attacker-supplied encoding
Summary
In PHP versions 8.4.* before 8.4.21 and 8.5.* before 8.5.6, when an encoding name containing an embedded NUL byte is passed to mb_convert_encoding() or related mbstring functions, the code incorrectly assumes that when strncasecmp() returns 0 it means the strings have the same length. This can lead to out-of-bounds read of global memory, potentially causing a crash or information disclosure or crash. Affected functions include mb_convert_encoding(), mb_detect_encoding(), mb_convert_variables(), and mb_detect_order(), as well as the mbstring.detect_order and mbstring.http_output INI settings.
Severity ?
CWE
- CWE-125 - Out-of-bounds Read
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
Credits
Akshay Jain
Ilija Tovilo
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-6104",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-05-11T13:04:44.572023Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-05-11T13:04:58.462Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
},
{
"affected": [
{
"cpes": [
"cpe:/o:redhat:enterprise_linux:10.2"
],
"defaultStatus": "affected",
"product": "Red Hat Enterprise Linux AppStream (v. 10)",
"vendor": "Red Hat"
},
{
"cpes": [
"cpe:/o:redhat:enterprise_linux:10"
],
"defaultStatus": "unaffected",
"product": "Red Hat Enterprise Linux 10",
"vendor": "Red Hat"
},
{
"cpes": [
"cpe:/o:redhat:enterprise_linux:6"
],
"defaultStatus": "unaffected",
"product": "Red Hat Enterprise Linux 6",
"vendor": "Red Hat"
},
{
"cpes": [
"cpe:/o:redhat:enterprise_linux:7"
],
"defaultStatus": "unaffected",
"product": "Red Hat Enterprise Linux 7",
"vendor": "Red Hat"
},
{
"cpes": [
"cpe:/o:redhat:enterprise_linux:8"
],
"defaultStatus": "unaffected",
"product": "Red Hat Enterprise Linux 8",
"vendor": "Red Hat"
},
{
"cpes": [
"cpe:/o:redhat:enterprise_linux:9"
],
"defaultStatus": "unaffected",
"product": "Red Hat Enterprise Linux 9",
"vendor": "Red Hat"
},
{
"cpes": [
"cpe:/a:redhat:hummingbird:1"
],
"defaultStatus": "unaffected",
"product": "Red Hat Hardened Images",
"vendor": "Red Hat"
}
],
"datePublic": "2026-05-10T04:35:17.328Z",
"descriptions": [
{
"lang": "en",
"value": "A flaw was found in PHP. When an encoding name containing an embedded NUL byte is passed to `mb_convert_encoding()` or related mbstring functions, an out-of-bounds read of only 1 byte can occur due to the incorrect processing of string lengths. This issue can cause a denial of service or limited information disclosure."
}
],
"metrics": [
{
"other": {
"content": {
"namespace": "https://access.redhat.com/security/updates/classification/",
"value": "Important"
},
"type": "Red Hat severity rating"
}
},
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 8.2,
"baseSeverity": "HIGH",
"confidentialityImpact": "LOW",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H",
"version": "3.1"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-125",
"description": "Out-of-bounds Read",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-06-30T12:11:10.359Z",
"orgId": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
"shortName": "redhat-SADP"
},
"references": [
{
"tags": [
"vdb-entry",
"x_refsource_REDHAT"
],
"url": "https://access.redhat.com/security/cve/CVE-2026-6104"
},
{
"name": "RHBZ#2468573",
"tags": [
"issue-tracking",
"x_refsource_REDHAT"
],
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2468573"
},
{
"tags": [
"x_sadp-csaf-vex"
],
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6104.json"
},
{
"tags": [
"vendor-advisory",
"x_refsource_REDHAT"
],
"url": "https://access.redhat.com/errata/RHSA-2026:22649"
}
],
"solutions": [
{
"lang": "en",
"value": "RHSA-2026:22649: Red Hat Enterprise Linux AppStream (v. 10)"
}
],
"timeline": [
{
"lang": "en",
"time": "2026-05-10T06:01:02.802Z",
"value": "Reported to Red Hat."
},
{
"lang": "en",
"time": "2026-05-10T04:35:17.328Z",
"value": "Made public."
}
],
"title": "php: global buffer over-read in mb_convert_encoding() with attacker-supplied encoding",
"workarounds": [
{
"lang": "en",
"value": "To mitigate this vulnerability, sanitize any input containing a NUL byte before calling the vulnerable mbstring functions. Also, verify your PHP configuration to ensure the vulnerable INI settings are using securely hardcoded encodings."
}
],
"x_adpType": "supplier",
"x_generator": {
"engine": "sadp-cli 1.0.0"
}
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"packageName": "mbstring",
"product": "PHP",
"vendor": "PHP Group",
"versions": [
{
"lessThan": "8.4.21",
"status": "affected",
"version": "8.4.*",
"versionType": "semver"
},
{
"lessThan": "8.5.6",
"status": "affected",
"version": "8.5.*",
"versionType": "semver"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "reporter",
"value": "Akshay Jain"
},
{
"lang": "en",
"type": "remediation developer",
"value": "Ilija Tovilo"
}
],
"datePublic": "2026-05-07T00:00:00.000Z",
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "In PHP versions 8.4.* before 8.4.21 and 8.5.* before 8.5.6, when an encoding name containing an embedded NUL byte is passed to \u003ccode\u003emb_convert_encoding()\u003c/code\u003e or related mbstring functions, the code incorrectly assumes that when\u0026nbsp;\u003ccode\u003estrncasecmp()\u003c/code\u003e\u0026nbsp;returns 0 it means the strings have the same length. This can lead to out-of-bounds read of global memory, potentially causing a crash or information disclosure or crash.\u003cspan\u003e\u0026nbsp;Affected functions include \u003c/span\u003e\u003ccode\u003emb_convert_encoding()\u003c/code\u003e\u003cspan\u003e, \u003c/span\u003e\u003ccode\u003emb_detect_encoding()\u003c/code\u003e\u003cspan\u003e, \u003c/span\u003e\u003ccode\u003emb_convert_variables()\u003c/code\u003e\u003cspan\u003e, and \u003c/span\u003e\u003ccode\u003emb_detect_order()\u003c/code\u003e\u003cspan\u003e, as well as the \u003c/span\u003e\u003ccode\u003embstring.detect_order\u003c/code\u003e\u003cspan\u003e and \u003c/span\u003e\u003ccode\u003embstring.http_output\u003c/code\u003e\u003cspan\u003e INI settings.\u003c/span\u003e"
}
],
"value": "In PHP versions 8.4.* before 8.4.21 and 8.5.* before 8.5.6, when an encoding name containing an embedded NUL byte is passed to mb_convert_encoding() or related mbstring functions, the code incorrectly assumes that when\u00a0strncasecmp()\u00a0returns 0 it means the strings have the same length. This can lead to out-of-bounds read of global memory, potentially causing a crash or information disclosure or crash.\u00a0Affected functions include mb_convert_encoding(), mb_detect_encoding(), mb_convert_variables(), and mb_detect_order(), as well as the mbstring.detect_order and mbstring.http_output INI settings."
}
],
"metrics": [
{
"cvssV4_0": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "PRESENT",
"attackVector": "NETWORK",
"baseScore": 6.3,
"baseSeverity": "MEDIUM",
"exploitMaturity": "NOT_DEFINED",
"privilegesRequired": "NONE",
"providerUrgency": "AMBER",
"subAvailabilityImpact": "LOW",
"subConfidentialityImpact": "LOW",
"subIntegrityImpact": "NONE",
"userInteraction": "NONE",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:L/SI:N/SA:L/RE:M/U:Amber",
"version": "4.0",
"vulnAvailabilityImpact": "LOW",
"vulnConfidentialityImpact": "LOW",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "MODERATE"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-125",
"description": "CWE-125 Out-of-bounds Read",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-05-10T04:35:17.328Z",
"orgId": "dd77f84a-d19a-4638-8c3d-a322d820ed2b",
"shortName": "php"
},
"references": [
{
"tags": [
"vendor-advisory"
],
"url": "https://github.com/php/php-src/security/advisories/GHSA-74r9-qxhc-fx53"
}
],
"source": {
"advisory": "GHSA-74r9-qxhc-fx53",
"discovery": "EXTERNAL"
},
"title": "Global buffer over-read in mb_convert_encoding() with attacker-supplied encoding",
"x_generator": {
"engine": "Vulnogram 0.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "dd77f84a-d19a-4638-8c3d-a322d820ed2b",
"assignerShortName": "php",
"cveId": "CVE-2026-6104",
"datePublished": "2026-05-10T04:35:17.328Z",
"dateReserved": "2026-04-11T04:15:03.938Z",
"dateUpdated": "2026-06-30T12:11:10.359Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"vulnrichment": {
"containers": "{\"adp\": [{\"title\": \"php: global buffer over-read in mb_convert_encoding() with attacker-supplied encoding\", \"metrics\": [{\"other\": {\"type\": \"Red Hat severity rating\", \"content\": {\"value\": \"Important\", \"namespace\": \"https://access.redhat.com/security/updates/classification/\"}}}, {\"format\": \"CVSS\", \"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 8.2, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"LOW\"}}], \"affected\": [{\"cpes\": [\"cpe:/o:redhat:enterprise_linux:10.2\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux AppStream (v. 10)\", \"defaultStatus\": \"affected\"}, {\"cpes\": [\"cpe:/o:redhat:enterprise_linux:10\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 10\", \"defaultStatus\": \"unaffected\"}, {\"cpes\": [\"cpe:/o:redhat:enterprise_linux:6\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 6\", \"defaultStatus\": \"unaffected\"}, {\"cpes\": [\"cpe:/o:redhat:enterprise_linux:7\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 7\", \"defaultStatus\": \"unaffected\"}, {\"cpes\": [\"cpe:/o:redhat:enterprise_linux:8\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 8\", \"defaultStatus\": \"unaffected\"}, {\"cpes\": [\"cpe:/o:redhat:enterprise_linux:9\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 9\", \"defaultStatus\": \"unaffected\"}, {\"cpes\": [\"cpe:/a:redhat:hummingbird:1\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Hardened Images\", \"defaultStatus\": \"unaffected\"}], \"timeline\": [{\"lang\": \"en\", \"time\": \"2026-05-10T06:01:02.802Z\", \"value\": \"Reported to Red Hat.\"}, {\"lang\": \"en\", \"time\": \"2026-05-10T04:35:17.328Z\", \"value\": \"Made public.\"}], \"solutions\": [{\"lang\": \"en\", \"value\": \"RHSA-2026:22649: Red Hat Enterprise Linux AppStream (v. 10)\"}], \"x_adpType\": \"supplier\", \"datePublic\": \"2026-05-10T04:35:17.328Z\", \"references\": [{\"url\": \"https://access.redhat.com/security/cve/CVE-2026-6104\", \"tags\": [\"vdb-entry\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://bugzilla.redhat.com/show_bug.cgi?id=2468573\", \"name\": \"RHBZ#2468573\", \"tags\": [\"issue-tracking\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6104.json\", \"tags\": [\"x_sadp-csaf-vex\"]}, {\"url\": \"https://access.redhat.com/errata/RHSA-2026:22649\", \"tags\": [\"vendor-advisory\", \"x_refsource_REDHAT\"]}], \"workarounds\": [{\"lang\": \"en\", \"value\": \"To mitigate this vulnerability, sanitize any input containing a NUL byte before calling the vulnerable mbstring functions. Also, verify your PHP configuration to ensure the vulnerable INI settings are using securely hardcoded encodings.\"}], \"x_generator\": {\"engine\": \"sadp-cli 1.0.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"A flaw was found in PHP. When an encoding name containing an embedded NUL byte is passed to `mb_convert_encoding()` or related mbstring functions, an out-of-bounds read of only 1 byte can occur due to the incorrect processing of string lengths. This issue can cause a denial of service or limited information disclosure.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-125\", \"description\": \"Out-of-bounds Read\"}]}], \"providerMetadata\": {\"orgId\": \"0b0ca135-0b70-47e7-9f44-1890c2a1c46c\", \"shortName\": \"redhat-SADP\", \"dateUpdated\": \"2026-06-30T03:18:37.380Z\"}}, {\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-6104\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-05-11T13:04:44.572023Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-05-11T13:04:53.269Z\"}}], \"cna\": {\"title\": \"Global buffer over-read in mb_convert_encoding() with attacker-supplied encoding\", \"source\": {\"advisory\": \"GHSA-74r9-qxhc-fx53\", \"discovery\": \"EXTERNAL\"}, \"credits\": [{\"lang\": \"en\", \"type\": \"reporter\", \"value\": \"Akshay Jain\"}, {\"lang\": \"en\", \"type\": \"remediation developer\", \"value\": \"Ilija Tovilo\"}], \"metrics\": [{\"format\": \"CVSS\", \"cvssV4_0\": {\"Safety\": \"NOT_DEFINED\", \"version\": \"4.0\", \"Recovery\": \"NOT_DEFINED\", \"baseScore\": 6.3, \"Automatable\": \"NOT_DEFINED\", \"attackVector\": \"NETWORK\", \"baseSeverity\": \"MEDIUM\", \"valueDensity\": \"NOT_DEFINED\", \"vectorString\": \"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:L/SI:N/SA:L/RE:M/U:Amber\", \"exploitMaturity\": \"NOT_DEFINED\", \"providerUrgency\": \"AMBER\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"attackRequirements\": \"PRESENT\", \"privilegesRequired\": \"NONE\", \"subIntegrityImpact\": \"NONE\", \"vulnIntegrityImpact\": \"NONE\", \"subAvailabilityImpact\": \"LOW\", \"vulnAvailabilityImpact\": \"LOW\", \"subConfidentialityImpact\": \"LOW\", \"vulnConfidentialityImpact\": \"LOW\", \"vulnerabilityResponseEffort\": \"MODERATE\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}], \"affected\": [{\"vendor\": \"PHP Group\", \"product\": \"PHP\", \"versions\": [{\"status\": \"affected\", \"version\": \"8.4.*\", \"lessThan\": \"8.4.21\", \"versionType\": \"semver\"}, {\"status\": \"affected\", \"version\": \"8.5.*\", \"lessThan\": \"8.5.6\", \"versionType\": \"semver\"}], \"packageName\": \"mbstring\", \"defaultStatus\": \"unaffected\"}], \"datePublic\": \"2026-05-07T00:00:00.000Z\", \"references\": [{\"url\": \"https://github.com/php/php-src/security/advisories/GHSA-74r9-qxhc-fx53\", \"tags\": [\"vendor-advisory\"]}], \"x_generator\": {\"engine\": \"Vulnogram 0.2.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"In PHP versions 8.4.* before 8.4.21 and 8.5.* before 8.5.6, when an encoding name containing an embedded NUL byte is passed to mb_convert_encoding() or related mbstring functions, the code incorrectly assumes that when\\u00a0strncasecmp()\\u00a0returns 0 it means the strings have the same length. This can lead to out-of-bounds read of global memory, potentially causing a crash or information disclosure or crash.\\u00a0Affected functions include mb_convert_encoding(), mb_detect_encoding(), mb_convert_variables(), and mb_detect_order(), as well as the mbstring.detect_order and mbstring.http_output INI settings.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"In PHP versions 8.4.* before 8.4.21 and 8.5.* before 8.5.6, when an encoding name containing an embedded NUL byte is passed to \u003ccode\u003emb_convert_encoding()\u003c/code\u003e or related mbstring functions, the code incorrectly assumes that when\u0026nbsp;\u003ccode\u003estrncasecmp()\u003c/code\u003e\u0026nbsp;returns 0 it means the strings have the same length. This can lead to out-of-bounds read of global memory, potentially causing a crash or information disclosure or crash.\u003cspan\u003e\u0026nbsp;Affected functions include \u003c/span\u003e\u003ccode\u003emb_convert_encoding()\u003c/code\u003e\u003cspan\u003e, \u003c/span\u003e\u003ccode\u003emb_detect_encoding()\u003c/code\u003e\u003cspan\u003e, \u003c/span\u003e\u003ccode\u003emb_convert_variables()\u003c/code\u003e\u003cspan\u003e, and \u003c/span\u003e\u003ccode\u003emb_detect_order()\u003c/code\u003e\u003cspan\u003e, as well as the \u003c/span\u003e\u003ccode\u003embstring.detect_order\u003c/code\u003e\u003cspan\u003e and \u003c/span\u003e\u003ccode\u003embstring.http_output\u003c/code\u003e\u003cspan\u003e INI settings.\u003c/span\u003e\", \"base64\": false}]}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-125\", \"description\": \"CWE-125 Out-of-bounds Read\"}]}], \"providerMetadata\": {\"orgId\": \"dd77f84a-d19a-4638-8c3d-a322d820ed2b\", \"shortName\": \"php\", \"dateUpdated\": \"2026-05-10T04:35:17.328Z\"}}}",
"cveMetadata": "{\"cveId\": \"CVE-2026-6104\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-06-30T03:18:37.380Z\", \"dateReserved\": \"2026-04-11T04:15:03.938Z\", \"assignerOrgId\": \"dd77f84a-d19a-4638-8c3d-a322d820ed2b\", \"datePublished\": \"2026-05-10T04:35:17.328Z\", \"assignerShortName\": \"php\"}",
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
Loading…