CVE-2025-4877: libssh vulnerabilities
Affects libsshSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 4.5 Medium · fixed in 0.6.3-4.3ubuntu0.6+esm2 : update libssh when convenient.
Data as of 27 Oct 2026, 06:42 UTC
- Patch
- Available – fixed in 0.6.3-4.3ubuntu0.6+esm2, 0.8.0~20170825.94fa1e38-1ubuntu0.7+esm4, 0.9.3-2ubuntu2.5+esm1
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:LExploitation evidence
Disclosed: evidence found.
CVE published 20 Aug 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade the Ubuntu libssh to 0.6.3-4.3ubuntu0.6+esm2 (package) or 0.8.0~20170825.94fa1e38-1ubuntu0.7+esm4 (package) or 0.9.3-2ubuntu2.5+esm1 (package).
Patches and advisories
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu Pro 20.04 LTSlibsshpkg:deb/ubuntu/libssh?arch=source&distro=esm-infra/focalOther threats | Affected
| Fixed in
|
Ubuntu Pro 18.04 LTSlibsshpkg:deb/ubuntu/libssh?arch=source&distro=esm-infra/bionicOther threats | Affected
| Fixed in
|
Ubuntu Pro 16.04 LTSlibsshpkg:deb/ubuntu/libssh?arch=source&distro=esm-infra/xenialOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
Ronald Crane discovered that libssh incorrectly handled certain base64 conversions. An attacker could use this issue to cause libssh to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2025-4877) Ronald Crane discovered that libssh incorrectly handled the privatekey_from_file() function. An attacker could use this issue to cause libssh to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2025-4878) Ronald Crane discovered that libssh incorrectly handled certain memory operations in the sftp server. An attacker could possibly use this issue to cause libssh to crash, resulting in a denial of service. (CVE-2025-5318)