Observable discrepancy in OpenSSH - CVE-2026-106582

Vulnerability details

The vulnerability allows a remote attacker to recover secret plaintext carried in another channel of an SSH connection.

The vulnerability exists due to observable ciphertext-length discrepancies in the shared LZ77 compression context used by ssh and sshd when multiplexed channels carry both secrets and attacker-controlled input. A remote attacker can introduce chosen plaintext into one channel and analyze the resulting ciphertext lengths to infer secrets transmitted through another channel.

Affected software

How to mitigate CVE-2026-106582

External References

• https://www.openssh.org/releasenotes.html#10.6
• https://arxiv.org/abs/2609.07709

Related Security Bulletins

• Multiple vulnerabilities in OpenSSH
• Anolis OS update for openssh