Vulnerability · Published Jul 21, 2026 · Assigned by redhat
CVE-2026-59844Libssh: libssh: denial of service via oversized sftp read length
Medium 6.5
In plain English
A medium-severity security flaw 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 0.6% (higher than 47% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.6%top 52.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
A flaw was found in libssh. A remote authenticated client can issue SSH_FXP_READ requests with an arbitrarily large length, causing a libssh SFTP server to allocate excessive memory and potentially exhaust it through repeated requests.
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-2026-59844 |
| Debian:12 | libssh | 0.10.6-0+deb12u3 | DEBIAN-CVE-2026-59844 |
| Debian:13 | libssh | 0.11.5-0+deb13u1 | DEBIAN-CVE-2026-59844 |
| Debian:14 | libssh | 0.12.1-1 | DEBIAN-CVE-2026-59844 |
| 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 | USN-8699-1 |
| Ubuntu:24.04:LTS | libssh | 0.10.6-2ubuntu0.5 | USN-8699-1 |
| Ubuntu:26.04:LTS | libssh | 0.11.3-1ubuntu2.1 | UBUNTU-CVE-2026-59844 |
| Ubuntu:26.04:LTS | libssh | 0.11.3-1ubuntu2.1 | USN-8699-1 |
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-789 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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-2026-59844 vdb-entry, x_refsource_REDHAT
- RHBZ#2498177 issue-tracking, x_refsource_REDHAT