CVE-2026-66034
HIGH
7,7
Source: [email protected]
Attack Vector: network
Attack Complexity: high
Privileges Required: none
User Interaction: passive
Confidentiality: N/A
Integrity: N/A
Availability: N/A
HIGH
7,5
Source: [email protected]
Attack Vector: network
Attack Complexity: high
Privileges Required: none
User Interaction: required
Scope: unchanged
Confidentiality: high
Integrity: high
Availability: high
Description
AI Translation Available
libssh2 through 1.11.1, fixed in commit a13bb6c, contains a missing bounds check vulnerability that allows a malicious SSH server to trigger an arbitrary-length heap out-of-bounds read and a free of an uninitialized pointer via the publickey subsystem. In libssh2_publickey_list_fetch(), the version 1 response parser reads a server-controlled comment_len value and advances the parse pointer without verifying sufficient bytes remain in the buffer, causing the out-of-bounds read to leak heap pointers from adjacent allocations defeating ASLR, followed by heap allocator state corruption when the error cleanup path frees an uninitialized pointer from a non-zeroed realloc() region.
125
Out-of-bounds Read
DraftCommon Consequences
Security Scopes Affected:
Confidentiality
Availability
Other
Potential Impacts:
Read Memory
Bypass Protection Mechanism
Dos: Crash, Exit, Or Restart
Varies By Context
Applicable Platforms
Languages:
Memory-Unsafe, C, C++
Technologies:
ICS/OT
908
Use of Uninitialized Resource
IncompleteCommon Consequences
Security Scopes Affected:
Confidentiality
Availability
Potential Impacts:
Read Memory
Read Application Data
Dos: Crash, Exit, Or Restart
Applicable Platforms
All platforms may be affected
https://github.com/libssh2/libssh2/commit/a13bb6c773f0d55ad1628cede57e99803cd89…
https://github.com/libssh2/libssh2/pull/2202
https://www.vulncheck.com/advisories/libssh2-heap-out-of-bounds-read-via-public…