CVE-2026-34826

Estado: AnalizadaAlta (7.5)—

Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Utils.get_byte_ranges parses the HTTP Range header without limiting the number of individual byte ranges. Although the existing fix for CVE-2024-26141 rejects ranges whose total byte coverage exceeds the file size, it does not restrict the count of ranges. An attacker can supply many small overlapping ranges such as 0-0,0-0,0-0,... to trigger disproportionate CPU, memory, I/O, and bandwidth consumption per request. This results in a denial of service condition in Rack file-serving paths that process multipart byte range responses. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Puntuación base: 7.5

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.46%
Percentil entre todas las CVEs puntuadas: 38
Fecha de la puntuación: 6/10/2026

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 access85 %
Impacto principalT1499.004 Application or System Exploitationimpact90 %

Vector CVSS AV:N/AC:L/PR:N/UI:N indica red sin privilegios. CWE-400 (uncontrolled resource consumption) y descripción explícita de DoS por consumo de CPU/memoria/I/O en Range header sin límite confirma T1499.004 (application exhaustion).

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

Filter Network Traffic Vulnerability Scanning Privileged Account Management Network Segmentation Limit Access to Resource Over Network Application Isolation and Sandboxing

Tecnologías afectadas (1)

Rack — Rack

CWE

CWE-400, CWE-770

Referencias

https://github.com/rack/rack/security/advisories/GHSA-x8cg-fq8g-mxfx

JSON original (NVD)

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