CVE-2026-55200
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.
- Published Jun 17, 2026
- CVSS 9.2 critical
- 0.8% chance of exploitation in the next 30 days (EPSS)
- Public exploit code is available
- A fix is available
Affected software
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