CVE-2026-86231 mwiede jsch KnownHosts.java getRevokedKeys improper check for certificate revocation
Attackers can bypass certificate revocation checks in the jsch library by manipulating known_hosts, potentially allowing connections to revoked keys.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-86231?
CVE-2026-86231 is a medium-severity vulnerability in mwiede jsch, published on 6 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A security flaw has been discovered in mwiede jsch up to 2.28.5. Affected is the function getRevokedKeys of the file src/main/java/com/jcraft/jsch/KnownHosts.java. Performing a manipulation of the argument known_hosts results in improper check for certificate revocation. The attack is possible to be carried out remotely. The attack is considered to have high complexity. The exploitability is told to be difficult. The exploit has been released to the public and may be used for attacks. Upgrading to version 2.28.6 is able to address this issue. The patch is named 194a2f76a5c0f1c3f778565be3fd66bcafc42d23. You should upgrade the affected component.
Which versions are affected by CVE-2026-86231?
Linux distribution packages (1)
jsch openSUSE:Tumbleweed | All versions | 2.28.7-1.1 |
How do I fix CVE-2026-86231?
Upgrade to a fixed version.
Is CVE-2026-86231 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-86231 exists.
Sources
Also known as CLEANSTART-2026-JS37598, CLEANSTART-2026-YJ32154, DEBIAN-CVE-2026-86231, GHSA-x2rp-h5qg-fmqg, UBUNTU-CVE-2026-86231, openSUSE-SU-2026:11814-1.