Description
A flaw was found in libssh. On servers with GSSAPIKeyExchange enabled, the gssapi-keyex path does not verify whether the authenticated Kerberos principal is authorized for the requested local user, allowing authenticated clients to log in as arbitrary users.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | — |
| Red Hat | Red Hat Hardened Images | — | — |
| Red Hat | Red Hat Enterprise Linux 8 | — | — |
| Red Hat | Red Hat Enterprise Linux 9 | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libssh | 0.12.1-1 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | libssh +2 | 0.12.0-3.el10_2 | RHSA-2026:55855 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Hardened Images 1 | libssh +2 | 0.12.1-4.hum1 | RHSA-2026:42922 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | libssh +2 | 0.12.0-3.el10_2 | ALSA-2026:55855 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | libssh | 0.12.0-3.el10_2 | RLSA-2026:55855 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | libssh | 0.12.1-r0 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | libssh +2 | 0.12.0-3.el10_2 | ELSA-2026-55855 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | libssh +1 | 0.12.1-r0 | — |
Advisories 6
- ALSA-2026:55855 Important: libssh security update AlmaLinux Security Advisories · Oct 29, 2026
- WID-SEC-2026-2428 libssh: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 22, 2026
- RHSA-2026:42922 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 6, 2026
- RHSA-2026:55855 Red Hat Security Advisory: libssh security update Red Hat Security Advisories (RHSA) · Sep 2, 2026
- RLSA-2026:55855 Important: libssh security update Rocky Linux Security Advisories · Aug 18, 2026
- ELSA-2026-55855 Important: libssh security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Aug 17, 2026
References
- RHSA-2026:42922 vendor-advisory
- RHSA-2026:55855 vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-59851 vdb-entry
- RHBZ#2498184 issue-tracking