CVE-2026-55200
libssh2 - Out-of-Bounds Write via Unchecked packet_length in transport.c
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fix or patch referenced
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
CISA's decision points: whether it is exploited, whether attacks can be automated, and how much control an attacker gets. Assessed (SSVC 2.0.3).What do these mean? →
- Exploitation: poc
- Automatable: no
- Technical impact: total
Summary
libssh2 1.11.1, fixed in commit 97acf3d, 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.
Timeline
- CISA SSVC assessment
Exploitation: poc · Automatable: no · Technical impact: total
- CVE published
- Record last updated
Affected versions
- libssh2 libssh2
From 1c3f1b7da588f2652260285529ec3c1f1125eb4e · fixed in 97acf3dfda80c91c3a8c9f2372546301d4a1a7a8