CVE-2026-55200

CRITICAL EPSS 55.8%
Published Jun 17, 20261w ago · Modified Jun 22, 20261w ago
9.2 CVSS 4.0
Critical
Find Similar
Published Jun 17, 2026 1w ago
Last Modified Jun 22, 2026 1w ago

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.

CVSS Details

Base Score
9.2
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
55.8% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-680

References 3

  • github.com https://github.com/libssh2/libssh2/commit/97acf3dfda80c91c3a8c9f2372546301d4a1a7a8
  • github.com https://github.com/libssh2/libssh2/pull/2052
  • vulncheck.com https://www.vulncheck.com/advisories/libssh2-out-of-bounds-write-via-unchecked-packet-length-in-transport-c

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.