CVE-2026-120263

Full vulnerability record from the local CVENow database.

Description

When `[oauth2_client].ACCOUNT_LINKING` is set to `auto` (not the default) and registration is enabled, the link-account sign-up form looked up the existing account to link by the user name or email submitted in the form instead of the identity asserted by the OAuth2 provider. An attacker with an account on a configured OAuth2 provider could submit another user's name, link their external identity to that Gitea account and be signed in as it without its password, including as an administrator. The link persisted for later sign-ins. Automatic linking now only happens when the existing account matches the provider's email or provider-derived user name; otherwise the account password is required.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Deferred

Source identifier

88ee5874-cf24-4952-aea0-31affedb7ff2

Published

2026-11-01 10:18:37.520000

Last modified

2026-11-01 10:18:37.637000

View original CVE JSON

{
  "id": "CVE-2026-120263",
  "sourceIdentifier": "88ee5874-cf24-4952-aea0-31affedb7ff2",
  "published": "2026-11-01T10:18:37.520",
  "lastModified": "2026-11-01T10:18:37.637",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "When `[oauth2_client].ACCOUNT_LINKING` is set to `auto` (not the default) and registration is enabled, the link-account sign-up form looked up the existing account to link by the user name or email submitted in the form instead of the identity asserted by the OAuth2 provider. An attacker with an account on a configured OAuth2 provider could submit another user's name, link their external identity to that Gitea account and be signed in as it without its password, including as an administrator. The link persisted for later sign-ins. Automatic linking now only happens when the existing account matches the provider's email or provider-derived user name; otherwise the account password is required."
    }
  ],
  "affected": [
    {
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2",
      "affectedData": [
        {
          "vendor": "Gitea",
          "product": "Gitea",
          "defaultStatus": "unaffected",
          "packageName": "gitea.dev",
          "versions": [
            {
              "version": "0",
              "lessThan": "28.3.0",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "weaknesses": [
    {
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-287"
        },
        {
          "lang": "en",
          "value": "CWE-639"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://blog.gitea.com/release-of-28.3.0/",
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2"
    },
    {
      "url": "https://github.com/go-gitea/gitea/pull/40121",
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2"
    },
    {
      "url": "https://github.com/go-gitea/gitea/pull/40137",
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2"
    },
    {
      "url": "https://github.com/go-gitea/gitea/releases/tag/v28.3.0",
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2"
    },
    {
      "url": "https://github.com/go-gitea/gitea/security/advisories/GHSA-8p3x-w464-4g6v",
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2"
    }
  ]
}