#VU125780 Information Exposure Through Timing Discrepancy in phpseclib
Published: April 10, 2026
Vulnerability identifier: #VU125780
Vulnerability risk: Low
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: N/A
CWE-ID: CWE-208
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
phpseclib
phpseclib
Software vendor:
phpseclib
phpseclib
Description
The vulnerability allows a remote attacker to disclose limited security-sensitive information via a timing side channel.
The vulnerability exists due to observable timing discrepancy in SSH2::get_binary_packet() in phpseclib/Net/SSH2.php when verifying received SSH packet HMAC values. A remote attacker can send specially crafted SSH packets to disclose limited security-sensitive information via a timing side channel.
The vulnerable code path is reached for non-AEAD cipher and MAC combinations, while AEAD cipher modes use a different authentication path.
Remediation
Install security update from vendor's website.