libssh2 - Pre-Authentication DoS via SSH_MSG_EXT_INFO Handler (libssh2 libssh2)
En bref
- Source
- NVD
- EPSS
- EPSS 0.92 % · centile 60 ()
- État
- PUBLISHED
- Publiée
- Mise à jour
- Attribuée par
- VulnCheck
- Statut NVD
- Analyzed
Rechercher sur…
Description
libssh2 through 1.11.1, fixed in commit 1762685, contains a pre-authentication denial of service vulnerability in the SSH_MSG_EXT_INFO handler in src/packet.c that allows a malicious SSH server to cause a client CPU exhaustion loop by sending a crafted extension count value. A malicious server can set nr_extensions to 0xFFFFFFFF during key exchange, causing the client to spin in a tight CPU loop for over 60 seconds because return values from _libssh2_get_string() are unchecked and the session timeout does not apply to CPU-bound loops.
Faiblesses (CWE)
- CWE-835 — Boucle dont la condition de sortie est inatteignable (boucle infinie)
Références
Scores
| Version | Score | Vecteur | Évalué par |
|---|---|---|---|
| CVSS 4.0 | HIGH 8.2 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N | VulnCheck |
| CVSS 3.1 | MEDIUM 5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H | VulnCheck |
| CVSS 4.0 | HIGH 8.2 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/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:X/R:X/V:X/RE:X/U:X | NVD · disclosure@vulncheck.com (Secondary) |
| CVSS 3.1 | MEDIUM 5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · disclosure@vulncheck.com (Secondary) |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · nvd@nist.gov (Primary) |
Références européennes
- ENISA EUVD · EUVD-2026-37782
- GCVE · GCVE-0-2026-55199
Avis du CERT-FR
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1352 — Multiples vulnérabilités dans Oracle PeopleSoft · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0841 — Multiples vulnérabilités dans Microsoft Azure Linux · cert.ssi.gouv.fr
Configurations affectées (CPE NVD)
cpe:2.3:a:libssh2:libssh2:*:*:*:*:*:*:*:*≤ 1.11.1
Produits affectés
| Produit | Versions |
|---|---|
| libssh2 · libssh2 | affected 0 ≤ 1.11.1 ; unaffected 17626857d20b3c9a1addfa45979dadcee1cd84a4 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |