CVE-2026-21916

Estado: AnalizadaAlta (7)—

A UNIX Symbolic Link (Symlink) Following vulnerability in the CLI of Juniper Networks Junos OS allows a local, authenticated attacker with low privileges to escalate their privileges to root which will lead to a complete compromise of the system.

When after a user has performed a specific 'file link ...' CLI operation, another user commits (unrelated configuration changes), the first user can login as root.

This issue does not affect versions 25.4R1 or later.

Detalles técnicos trazas, registros y código del informe original

This issue affects Junos OS:
  *  all versions before 23.2R2-S7,
  *  23.4 versions before 23.4R2-S6,
  *  24.2 versions before 24.2R2-S3,
  *  24.4 versions before 24.4R2-S2,
  *  25.2 versions before 25.2R2.

CVSS

Versión: 4.0
Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:U/V:X/RE:M/U:X
Puntuación base: 7

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.13%
Percentil entre todas las CVEs puntuadas: 2
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.

ExplotaciónT1203 Exploitation for Client Executionexecution60 %

Inferido por reglas deterministas a partir del vector CVSS y la CWE. Solo orientativo.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Application Isolation and Sandboxing Exploit Protection Update Software

Tecnologías afectadas (1)

Juniper — Junos

CWE

CWE-61

Referencias

https://kb.juniper.net/JSA107807

JSON original (NVD)

Mostrar

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