| Name | CVE-2026-55200 |
| Description | libssh2 through 1.11.1, fixed in commit 7acf3df contains an out-of-bounds write vulnerability in ssh2_transport_read() that fails to enforce upper bounds on packet_length field. Remote attackers can send crafted SSH packets with excessively large packet_length values to corrupt heap memory and achieve remote code execution. |
| 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-6365-1 |
| Debian Bugs | 1140401 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| libssh2 (PTS) | bullseye | 1.9.0-2+deb11u1 | fixed |
| bookworm | 1.10.0-3 | fixed |
| trixie (security), trixie | 1.11.1-1+deb13u1 | fixed |
| forky | 1.11.1-5 | fixed |
| sid | 1.11.1-6 | fixed |
The information below is based on the following data on fixed versions.
Notes
[bookworm] - libssh2 <not-affected> (Vulnerable code not present)
[bullseye] - libssh2 <not-affected> (Vulnerable code not present)
https://github.com/libssh2/libssh2/pull/2052
Fixed by: https://github.com/libssh2/libssh2/commit/97acf3dfda80c91c3a8c9f2372546301d4a1a7a8