CVE-2026-20897

Status: ModifiedCritical (9.1)—

Gitea does not properly validate repository ownership when deleting Git LFS locks. A user with write access to one repository may be able to delete LFS locks belonging to other repositories.

CVSS

Version: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Base score: 9.1

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 0.46%
Percentile among all scored CVEs: 38
Score date: 10/6/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

🎯 ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

ExploitationT1190 Exploit Public-Facing Applicationinitial access85 %
Primary impactT1565.002 Transmitted Data Manipulationimpact75 %
Secondary impactT1531 Account Access Removalimpact65 %

AV:N/PR:N sin UI indica explotación remota sin privilegios (T1190). La validación deficiente de propiedad permite manipular LFS locks ajenos (T1565.002: modificación de datos). Afecta integridad de repositorios y potencial denegación de acceso a colaboradores (T1531).

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

🛡️ ATT&CK mitigations that cover these techniques

Vulnerability Scanning Privileged Account Management Network Segmentation Limit Access to Resource Over Network Filter Network Traffic Encrypt Sensitive Information

Affected technologies (1)

Gitea — Gitea

CWEs

CWE-284, CWE-639
CWE-639

References

Raw JSON (NVD)

Show

{
  "id": "CVE-2026-20897",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-20897",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-01-23T17:56:55.236953Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 9.1,
          "attackVector": "NETWORK",
          "baseSeverity": "CRITICAL",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.2,
        "exploitabilityScore": 3.9
      },
      {
        "type": "Secondary",
        "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 9.1,
          "attackVector": "NETWORK",
          "baseSeverity": "CRITICAL",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.2,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2",
      "affectedData": [
        {
          "vendor": "Gitea",
          "product": "Gitea Open Source Git Server",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "versionType": "semver",
              "lessThanOrEqual": "1.25.3"
            }
          ],
          "defaultStatus": "unaffected"
        }
      ]
    },
    {
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
      "affectedData": [
        {
          "cpes": [
            "cpe:/a:redhat:openshift_pipelines:1"
          ],
          "vendor": "Red Hat",
          "product": "OpenShift Pipelines",
          "packageName": "openshift-pipelines/pipelines-opc-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:openshift_pipelines:1"
          ],
          "vendor": "Red Hat",
          "product": "OpenShift Pipelines",
          "packageName": "openshift-pipelines/pipelines-pipelines-as-code-cli-rhel8",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:openshift_pipelines:1"
          ],
          "vendor": "Red Hat",
          "product": "OpenShift Pipelines",
          "packageName": "openshift-pipelines/pipelines-pipelines-as-code-cli-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:openshift_pipelines:1"
          ],
          "vendor": "Red Hat",
          "product": "OpenShift Pipelines",
          "packageName": "openshift-pipelines/pipelines-pipelines-as-code-controller-rhel8",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:openshift_pipelines:1"
          ],
          "vendor": "Red Hat",
          "product": "OpenShift Pipelines",
          "packageName": "openshift-pipelines/pipelines-pipelines-as-code-controller-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:openshift_pipelines:1"
          ],
          "vendor": "Red Hat",
          "product": "OpenShift Pipelines",
          "packageName": "openshift-pipelines/pipelines-pipelines-as-code-watcher-rhel8",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:openshift_pipelines:1"
          ],
          "vendor": "Red Hat",
          "product": "OpenShift Pipelines",
          "packageName": "openshift-pipelines/pipelines-pipelines-as-code-watcher-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:openshift_pipelines:1"
          ],
          "vendor": "Red Hat",
          "product": "OpenShift Pipelines",
          "packageName": "openshift-pipelines/pipelines-pipelines-as-code-webhook-rhel8",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:openshift_pipelines:1"
          ],
          "vendor": "Red Hat",
          "product": "OpenShift Pipelines",
          "packageName": "openshift-pipelines/pipelines-pipelines-as-code-webhook-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        }
      ]
    }
  ],
  "published": "2026-01-22T22:16:18.960",
  "references": [
    {
      "url": "https://blog.gitea.com/release-of-1.25.4/",
      "tags": [
        "Release Notes"
      ],
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2"
    },
    {
      "url": "https://github.com/go-gitea/gitea/pull/36344",
      "tags": [
        "Issue Tracking",
        "Patch"
      ],
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2"
    },
    {
      "url": "https://github.com/go-gitea/gitea/pull/36349",
      "tags": [
        "Issue Tracking",
        "Patch"
      ],
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2"
    },
    {
      "url": "https://github.com/go-gitea/gitea/releases/tag/v1.25.4",
      "tags": [
        "Release Notes"
      ],
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2"
    },
    {
      "url": "https://github.com/go-gitea/gitea/security/advisories/GHSA-rrq5-r9h5-pc7c",
      "tags": [
        "Broken Link"
      ],
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2"
    },
    {
      "url": "https://access.redhat.com/security/cve/CVE-2026-20897",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2432204",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-20897.json",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2",
      "description": [
        {
          "lang": "en",
          "value": "CWE-284"
        },
        {
          "lang": "en",
          "value": "CWE-639"
        }
      ]
    },
    {
      "type": "Secondary",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
      "description": [
        {
          "lang": "en",
          "value": "CWE-639"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Gitea does not properly validate repository ownership when deleting Git LFS locks. A user with write access to one repository may be able to delete LFS locks belonging to other repositories."
    },
    {
      "lang": "es",
      "value": "Gitea no valida correctamente la propiedad del repositorio al eliminar bloqueos de Git LFS. Un usuario con acceso de escritura a un repositorio podría eliminar bloqueos LFS pertenecientes a otros repositorios."
    }
  ],
  "lastModified": "2026-07-15T02:18:24.600",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:gitea:gitea:*:*:*:*:*:-:*:*",
              "vulnerable": true,
              "matchCriteriaId": "DFCB7D74-331D-4582-AB41-113A25BE8FAA",
              "versionEndExcluding": "1.25.4"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "88ee5874-cf24-4952-aea0-31affedb7ff2"
}