CVE-2026-55200
HIGHlibssh2 - Out-of-Bounds Write via Unchecked packet_length in transport.c
Title source: cnaDescription
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.
References (3)
Core 3
Core References
Patch patch
Patch Commit
https://github.com/libssh2/libssh2/commit/97acf3dfda80c91c3a8c9f2372546301d4a1a7a8
Third Party Advisory third-party-advisory
https://www.vulncheck.com/advisories/libssh2-out-of-bounds-write-via-unchecked-packet-length-in-transport-c
Scores
CVSS v3
8.1
EPSS
0.0055
EPSS Percentile
41.7%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
total
Details
CWE
CWE-680
Status
published
Products (2)
libssh2/libssh2
< 1.11.1
libssh2/libssh2
7acf3dfda80c91c3a8c9f2372546301d4a1a7a8
Published
Jun 17, 2026
Tracked Since
Jun 18, 2026