| Name | CVE-2026-59843 |
| Description | A flaw was found in libssh. A remote authenticated peer can advertise a zero maximum packet size in SSH_MSG_CHANNEL_OPEN, causing later channel writes to loop indefinitely and consume CPU, leading to denial of service. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DSA-6410-1 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| libssh (PTS) | bullseye | 0.9.8-0+deb11u1 | vulnerable |
| bullseye (security) | 0.9.8-0+deb11u2 | vulnerable | |
| bookworm | 0.10.6-0+deb12u2 | vulnerable | |
| bookworm (security) | 0.10.6-0+deb12u1 | vulnerable | |
| trixie | 0.11.2-1+deb13u1 | vulnerable | |
| trixie (security) | 0.11.5-0+deb13u1 | fixed | |
| forky, sid | 0.12.2-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| libssh | source | trixie | 0.11.5-0+deb13u1 | DSA-6410-1 | ||
| libssh | source | (unstable) | 0.12.2-1 |
https://www.libssh.org/2026/07/28/libssh-0-12-2-security-release/
https://www.libssh.org/security/advisories/CVE-2026-59843.txt
Fixed by: https://git.libssh.org/projects/libssh.git/commit/?id=3f785905760d2e2a87037285ab85b37b9924e409 (libssh-0.12.2)
Fixed by: https://git.libssh.org/projects/libssh.git/commit/?id=006ddd503566ee13e00db42bc111e898388f8664 (libssh-0.12.2)