CVE-2026-26247

{
  "id": "CVE-2026-26247",
  "sourceIdentifier": "88ee5874-cf24-4952-aea0-31affedb7ff2",
  "published": "2026-07-03T21:16:58.417",
  "lastModified": "2026-10-25T15:10:00.147",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "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."
    },
    {
      "lang": "es",
      "value": "Las versiones de Gitea anteriores a la 1.25.5 no persisten correctamente el método de desafío OAuth2 PKCE S256 durante la autorización, permitiendo el intercambio de tokens sin la verificación del verificador esperada."
    }
  ],
  "affected": [
    {
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2",
      "affectedData": [
        {
          "vendor": "Gitea",
          "product": "Gitea Open Source Git Server",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "0",
              "lessThan": "1.25.5",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
          "baseScore": 9.1,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.2
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-07-07T16:21:34.783006Z",
          "id": "CVE-2026-26247",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-284"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://blog.gitea.com/release-of-1.25.5/",
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2"
    },
    {
      "url": "https://github.com/go-gitea/gitea/pull/36462",
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2"
    },
    {
      "url": "https://github.com/go-gitea/gitea/pull/36477",
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2"
    },
    {
      "url": "https://github.com/go-gitea/gitea/releases/tag/v1.25.5",
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2"
    }
  ]
}