CVE-2026-26247

Estado: AplazadaCrítica (9.1)—

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.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Puntuación base: 9.1

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.50%
Percentil entre todas las CVEs puntuadas: 40
Fecha de la puntuación: 5/10/2026

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

ExplotaciónT1190 Exploit Public-Facing Applicationinitial access95 %
Impacto principalT1078.004 Cloud Accountsstealth · persistence · privilege escalation · initial access85 %
Impacto secundarioT1098.001 Additional Cloud Credentialspersistence · privilege escalation80 %

CVE-2026-26247 afecta OAuth2 en Gitea sin privilegios previos (AV:N, PR:N) permitiendo bypass de verificación PKCE para obtener tokens de acceso sin autenticación legítima, resultando en account/token takeover.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Privileged Account Management User Account Management Network Segmentation Multi-factor Authentication Active Directory Configuration Vulnerability Scanning

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Gitea — Gitea^AI

CWE

CWE-284

Referencias

JSON original (NVD)

Mostrar

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  "id": "CVE-2026-26247",
  "cveTags": [],
  "metrics": {
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      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-26247",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-07-07T16:21:34.783006Z"
        }
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    "cvssMetricV31": [
      {
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          "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
      }
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      "affectedData": [
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          "vendor": "Gitea",
          "product": "Gitea Open Source Git Server",
          "versions": [
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              "version": "0",
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  "published": "2026-07-03T21:16:58.417",
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      "source": "88ee5874-cf24-4952-aea0-31affedb7ff2"
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      "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."
    }
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  "lastModified": "2026-07-07T18:16:37.327",
  "sourceIdentifier": "88ee5874-cf24-4952-aea0-31affedb7ff2"
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