CVE-2026-55200

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.
NVD Severity
unknown
Other trackers
CVE, NVD, CERT, CVE Details, CIRCL, Arch Linux, Debian, Red Hat, Ubuntu, Gentoo, SUSE (Bugzilla), SUSE (CVE), Mageia
Mailing lists
oss-security, full-disclosure, bugtraq
Exploits
Exploit DB, Metasploit
Forges
GitHub (code, issues), Aports (code, issues)

References

Type URI
disclosure@vulncheck.com https://github.com/libssh2/libssh2/commit/97acf3dfda80c91c3a8c9f2372546301d4a1a7a8
disclosure@vulncheck.com https://github.com/libssh2/libssh2/pull/2052
disclosure@vulncheck.com https://www.vulncheck.com/advisories/libssh2-out-of-bounds-write-via-unchecked-packet-length-in-transport-c
134c704f-9b21-4f2e-91b3-4a467353bcc0 https://github.com/bikini/exploitarium/tree/main/libssh2-cve-2026-55200-poc
134c704f-9b21-4f2e-91b3-4a467353bcc0 https://web.archive.org/web/20260623211210/https://github.com/bikini/exploitarium/tree/main/libssh2-cve-2026-55200-poc

Match rules

CPE URI Source package Min version Max version
cpe:2.3:a:libssh2:libssh2:*:*:*:*:*:*:*:* libssh2 >= None <= 1.11.1

Vulnerable and fixed packages

Source package Branch Version Maintainer Status
rust edge-main 1.96.1-r0 team/rust <alpine@ptrcnull.me> fixed
libssh2 edge-main 1.11.1-r3 Natanael Copa <ncopa@alpinelinux.org> fixed
libssh2 edge-main 1.11.1-r2 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
libssh2 edge-main 1.11.1-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
libssh2 edge-main 1.11.1-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
libssh2 edge-main 1.11.0-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
libssh2 edge-main 1.9.0-r2 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
libssh2 edge-main 1.9.0-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
libssh2 edge-main 1.9.0-r0 None possibly vulnerable
libssh2 edge-main 1.8.1-r0 None possibly vulnerable
libssh2 3.24-main 1.11.1-r3 Natanael Copa <ncopa@alpinelinux.org> fixed
libssh2 3.24-main 1.11.1-r2 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
libssh2 3.23-main 1.11.1-r3 Natanael Copa <ncopa@alpinelinux.org> fixed
libssh2 3.23-main 1.11.1-r2 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
libssh2 3.23-main 1.11.1-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
libssh2 3.22-main 1.11.1-r2 Natanael Copa <ncopa@alpinelinux.org> fixed
libssh2 3.22-main 1.11.1-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
libssh2 3.22-main 1.11.1-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
libssh2 3.22-main 1.11.0-r1 None possibly vulnerable
libssh2 3.22-main 1.9.0-r1 None possibly vulnerable
libssh2 3.22-main 1.9.0-r0 None possibly vulnerable
libssh2 3.22-main 1.8.1-r0 None possibly vulnerable
libssh2 3.21-main 1.11.1-r2 Natanael Copa <ncopa@alpinelinux.org> fixed
libssh2 3.21-main 1.11.1-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
libssh2 3.21-main 1.11.1-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
libssh2 3.21-main 1.11.0-r1 None possibly vulnerable
libssh2 3.21-main 1.9.0-r1 None possibly vulnerable
libssh2 3.21-main 1.9.0-r0 None possibly vulnerable
libssh2 3.21-main 1.8.1-r0 None possibly vulnerable
libssh2 3.20-main 1.11.0-r3 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
libssh2 3.20-main 1.11.0-r2 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
libssh2 3.20-main 1.11.0-r1 None possibly vulnerable
libssh2 3.20-main 1.9.0-r1 None possibly vulnerable
libssh2 3.20-main 1.9.0-r0 None possibly vulnerable
libssh2 3.20-main 1.8.1-r0 None possibly vulnerable
libssh2 3.19-main 1.11.0-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
libssh2 3.19-main 1.9.0-r1 None possibly vulnerable
libssh2 3.19-main 1.9.0-r0 None possibly vulnerable
libssh2 3.19-main 1.8.1-r0 None possibly vulnerable