Vulnerability · Published Jul 21, 2026 · Assigned by redhat
CVE-2026-59846Libssh: libssh: information disclosure via proxycommand %r username expansion
Low 3.9
In plain English
A low-severity OS command injection in Red Hat Enterprise Linux 10 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)3.9Low
Exploit odds (30 days)0.1%top 98.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
A flaw was found in libssh. A malicious username expanded through %r in ProxyCommand handling can inject shell metacharacters, exposing environment variables and causing unintended shell behavior.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | libssh | 0.12.0-3.el10_2 | ALSA-2026:55855 |
| AlmaLinux:8 | libssh | 0.9.6-17.el8_10 | ALSA-2026:62218 |
| AlmaLinux:9 | libssh | 0.10.4-19.el9_8 | ALSA-2026:62217 |
| AlmaLinux:10 | libssh-config | 0.12.0-3.el10_2 | ALSA-2026:55855 |
| AlmaLinux:8 | libssh-config | 0.9.6-17.el8_10 | ALSA-2026:62218 |
| AlmaLinux:9 | libssh-config | 0.10.4-19.el9_8 | ALSA-2026:62217 |
| AlmaLinux:10 | libssh-devel | 0.12.0-3.el10_2 | ALSA-2026:55855 |
| AlmaLinux:8 | libssh-devel | 0.9.6-17.el8_10 | ALSA-2026:62218 |
| AlmaLinux:9 | libssh-devel | 0.10.4-19.el9_8 | ALSA-2026:62217 |
| Alpine:v3.24 | libssh | 0.12.1-r0 | ALPINE-CVE-2026-59846 |
| Debian:12 | libssh | 0.10.6-0+deb12u3 | DEBIAN-CVE-2026-59846 |
| Debian:13 | libssh | 0.11.5-0+deb13u1 | DEBIAN-CVE-2026-59846 |
| Debian:14 | libssh | 0.12.1-1 | DEBIAN-CVE-2026-59846 |
| Rocky Linux:10 | libssh | 0:0.12.0-3.el10_2 | RLSA-2026:55855 |
| Rocky Linux:8 | libssh | 0:0.9.6-17.el8_10 | RLSA-2026:62218 |
| Rocky Linux:9 | libssh | 0:0.10.4-19.el9_8 | RLSA-2026:62217 |
| Ubuntu:22.04:LTS | libssh | 0.9.6-2ubuntu0.22.04.8 | UBUNTU-CVE-2026-59846 |
| Ubuntu:22.04:LTS | libssh | 0.9.6-2ubuntu0.22.04.8 | USN-8699-1 |
| Ubuntu:24.04:LTS | libssh | 0.10.6-2ubuntu0.5 | UBUNTU-CVE-2026-59846 |
| Ubuntu:24.04:LTS | libssh | 0.10.6-2ubuntu0.5 | USN-8699-1 |
| Ubuntu:26.04:LTS | libssh | 0.11.3-1ubuntu2.1 | USN-8699-1 |
| Ubuntu:26.04:LTS | libssh | 0.11.3-1ubuntu2.1 | UBUNTU-CVE-2026-59846 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | see references |
| Red Hat | Red Hat Enterprise Linux 8 | see references |
| Red Hat | Red Hat Enterprise Linux 8 | see references |
| Red Hat | Red Hat Enterprise Linux 9 | see references |
| Red Hat | Red Hat Enterprise Linux 9 | see references |
| Red Hat | Red Hat Hardened Images | see references |
Weakness: CWE-78, CWE-77 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N
References
- RHSA-2026:42922 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:55855 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:62217 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:62218 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-59846 vdb-entry, x_refsource_REDHAT
- RHBZ#2498179 issue-tracking, x_refsource_REDHAT