CVE-2025-8277
Libssh: memory exhaustion via repeated key exchange in libssh
At a glance
- Severity
- LOW 3.1
- EPSS
- EPSS 0.43 % · percentile 37 (2026-10-27)
- State
- PUBLISHED
- Published
- Updated
- Assigner
- redhat
- NVD status
- Deferred
Description
A flaw was found in libssh's handling of key exchange (KEX) processes when a client repeatedly sends incorrect KEX guesses. The library fails to free memory during these rekey operations, which can gradually exhaust system memory. This issue can lead to crashes on the client side, particularly when using libgcrypt, which impacts application stability and availability.
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | LOW 3.1 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L | redhat |
| CVSS 3.1 | LOW 3.1 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L | NVD · secalert@redhat.com (Secondary) |
Weaknesses (CWE)
European references
- ENISA EUVD · EUVD-2025-27246
- GCVE · GCVE-0-2025-8277
CERT-FR advisories
- CERTFR-2026-AVI-0326 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0316 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0209 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0969 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
Affected products
| Product | Versions |
|---|---|
| libssh | affected 0.6.0 < 0.11.3 |
| Red Hat · Red Hat Enterprise Linux 9 | unaffected 0:0.10.4-18.el9 < * |
| Red Hat · Red Hat Enterprise Linux 9 | unaffected 0:0.10.4-18.el9 < * |
| Red Hat · Red Hat Enterprise Linux 10 | |
| Red Hat · Red Hat Enterprise Linux 6 | |
| Red Hat · Red Hat Enterprise Linux 7 | |
| Red Hat · Red Hat Enterprise Linux 8 | |
| Red Hat · Red Hat OpenShift Container Platform 4 | |
| Red Hat · Red Hat OpenShift Container Platform 4 |
References
- https://access.redhat.com/errata/RHSA-2026:18683
- https://access.redhat.com/security/cve/CVE-2025-8277
- https://bugzilla.redhat.com/show_bug.cgi?id=2383888
- https://www.libssh.org/security/advisories/CVE-2025-8277.txt
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 |