CVE-2026-20896

{
  "id": "CVE-2026-20896",
  "sourceIdentifier": "88ee5874-cf24-4952-aea0-31affedb7ff2",
  "published": "2026-07-03T21:16:56.660",
  "lastModified": "2026-10-25T15:10:00.147",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Gitea Docker image versions up to and including 1.26.2 use REVERSE_PROXY_TRUSTED_PROXIES=* by default, allowing any source IP to impersonate a user when reverse-proxy authentication headers such as X-WEBAUTH-USER are enabled."
    },
    {
      "lang": "es",
      "value": "Las versiones de la imagen Docker de Gitea hasta e incluyendo la 1.26.2 usan REVERSE_PROXY_TRUSTED_PROXIES=* por defecto, permitiendo que cualquier IP de origen suplante la identidad de un usuario cuando los encabezados de autenticación de proxy inverso como X-WEBAUTH-USER están habilitados."
    }
  ],
  "affected": [
    {
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2",
      "affectedData": [
        {
          "vendor": "Gitea",
          "product": "Gitea Open Source Git Server",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "0",
              "lessThanOrEqual": "1.26.2",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "88ee5874-cf24-4952-aea0-31affedb7ff2",
        "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:H",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-07-06T19:03:07.590667Z",
          "id": "CVE-2026-20896",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "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-1.26.3-and-1.26.4/",
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2"
    },
    {
      "url": "https://github.com/go-gitea/gitea/pull/38151",
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2"
    },
    {
      "url": "https://github.com/go-gitea/gitea/releases/tag/v1.26.3",
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2"
    },
    {
      "url": "https://github.com/go-gitea/gitea/security/advisories/GHSA-f75j-4cw6-rmx4",
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2"
    },
    {
      "url": "https://github.com/go-gitea/gitea/security/advisories/GHSA-f75j-4cw6-rmx4",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ]
}