CVE-2026-26247 (GCVE-0-2026-26247)

Vulnerability from cvelistv5 – Published: 2026-07-03 20:19 – Updated: 2026-07-03 20:19
VLAI?
Title
Gitea OAuth2 PKCE S256 challenges are not enforced during token exchange
Summary
Gitea versions before 1.25.5 do not persist the OAuth2 PKCE S256 challenge method correctly during authorization, allowing token exchange without the expected verifier check.
Severity ?
No CVSS data available.
CWE
Assigner
References
Impacted products
Vendor Product Version
Gitea Gitea Open Source Git Server Affected: 0 , < 1.25.5 (semver)
Create a notification for this product.
Credits
Aisle Research
Show details on NVD website
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Gitea Open Source Git Server",
          "vendor": "Gitea",
          "versions": [
            {
              "lessThan": "1.25.5",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "Aisle Research"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Gitea versions before 1.25.5 do not persist the OAuth2 PKCE S256 challenge method correctly during authorization, allowing token exchange without the expected verifier check."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-284",
              "description": "CWE-284",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-03T20:19:34.820Z",
        "orgId": "88ee5874-cf24-4952-aea0-31affedb7ff2",
        "shortName": "Gitea"
      },
      "references": [
        {
          "name": "GitHub Pull Request #36462",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/go-gitea/gitea/pull/36462"
        },
        {
          "name": "GitHub Pull Request #36477",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/go-gitea/gitea/pull/36477"
        },
        {
          "name": "Gitea v1.25.5 Release",
          "tags": [
            "release-notes"
          ],
          "url": "https://github.com/go-gitea/gitea/releases/tag/v1.25.5"
        },
        {
          "name": "Gitea v1.25.5 Release Blog Post",
          "tags": [
            "release-notes"
          ],
          "url": "https://blog.gitea.com/release-of-1.25.5/"
        }
      ],
      "title": "Gitea OAuth2 PKCE S256 challenges are not enforced during token exchange",
      "x_generator": {
        "engine": "cvelib 1.8.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "88ee5874-cf24-4952-aea0-31affedb7ff2",
    "assignerShortName": "Gitea",
    "cveId": "CVE-2026-26247",
    "datePublished": "2026-07-03T20:19:34.820Z",
    "dateReserved": "2026-03-03T03:25:28.654Z",
    "dateUpdated": "2026-07-03T20:19:34.820Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.