CVE-2025-4877

Libssh: write beyond bounds in binary to base64 conversion functions

MEDIUM
4.5
CVSS Score
Published: August 20, 2025 at 12:19 PM UTC
Updated: August 31, 2026 at 12:17 PM UTC
Products not identified yet

Using N/A by N/A?

Get instant alerts when new vulnerabilities affect N/A - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
MEDIUM4.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

There's a vulnerability in the libssh package where when a libssh consumer passes in an unexpectedly large input buffer to ssh_get_fingerprint_hash() function. In such cases the bin_to_base64() function can experience an integer overflow leading to a memory under allocation, when that happens it's possible that the program perform out of bounds write leading to a heap corruption. This issue affects only 32-bits builds of libssh.

Affected

We have no canonical product record for this CVE. The source names may not have matched any product.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.5MEDIUMredhat
Attack Vector
LOCAL
Complexity
HIGH
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
LOW
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-787

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card