Ubuntu 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS / Pro Realtime 22.04 LTS : phpseclib vulnerability (USN-8769-1)

The remote Ubuntu 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS / Pro Realtime 22.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-8769-1 advisory. It was discovered that phpseclib did not perform padding validation in constant...

USN-8769-1 phpseclib vulnerability

It was discovered that phpseclib did not perform padding validation in constant time when using AES in CBC mode. A remote attacker could possibly use this issue to conduct a padding oracle timing attack and obtain sensitive information...

USN-8769-1: phpseclib vulnerability

It was discovered that phpseclib did not perform padding validation in constant time when using AES in CBC mode. A remote attacker could possibly use this issue to conduct a padding oracle timing attack and obtain sensitive information...

CVE-2026-84308

A flaw was found in phpseclib, a PHP secure communications library. This vulnerability arises from non-constant-time X25519 scalar multiplication, where data-dependent conditional modular reductions create observable timing differences or variations in libgmp call counts. A local attacker, capabl...

EUVD-2026-69576

phpseclib — non-constant-time X25519 scalar multiplication permits full private-key recovery...

phpseclib — non-constant-time X25519 scalar multiplication permits full private-key recovery

The pure-PHP X25519 scalar multiplication in phpseclib is not constant-time. Field addition and subtraction each perform a data-dependent conditional modular reduction, so the cost of each Montgomery-ladder step is a linear function of that step's reduction count which is a quantity determined by...

GHSA-Q97C-8QH3-FPC6 phpseclib — non-constant-time X25519 scalar multiplication permits full private-key recovery

The pure-PHP X25519 scalar multiplication in phpseclib is not constant-time. Field addition and subtraction each perform a data-dependent conditional modular reduction, so the cost of each Montgomery-ladder step is a linear function of that step's reduction count which is a quantity determined by...

ROS-20260904-73-0006

The vulnerability in php-phpseclib is related to manipulating an unknown input, resulting in a time mismatch. Exploiting this vulnerability can allow an attacker, operating remotely, to gain unauthorized access to protected information...

ROS-20260904-73-0007

The vulnerability in php-phpseclib is related to an uncontrolled resource consumption. Exploiting this vulnerability can allow a malicious actor to cause service failures...

Linux Distros Unpatched Vulnerability : CVE-2026-84308

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - phpseclib is a PHP secure communications library. Prior to 3.0.57 and 4.0.1, pure-PHP X25519 scalar multiplication in phpseclib/Math/PrimeField/Integer.php...

Timing Attack

Overview phpseclib/phpseclib is a PHP Secure Communications Library - Pure-PHP implementations of RSA, AES, SSH2, SFTP, X.509 etc. Affected versions of this package are vulnerable to Timing Attack the pure-PHP X25519 scalar multiplication in Crypt/EC/Formats/Keys/MontgomeryPrivate.php,...

CVE-2026-84308

phpseclib is a PHP secure communications library. Prior to 3.0.57 and 4.0.1, pure-PHP X25519 scalar multiplication in phpseclib/Math/PrimeField/Integer.php performs data-dependent conditional modular reductions in add and subtract. During the Montgomery ladder in...

DEBIAN-CVE-2026-84308

phpseclib is a PHP secure communications library. Prior to 3.0.57 and 4.0.1, pure-PHP X25519 scalar multiplication in phpseclib/Math/PrimeField/Integer.php performs data-dependent conditional modular reductions in add and subtract. During the Montgomery ladder in...

CVE-2026-84308

phpseclib is a PHP secure communications library. Prior to 3.0.57 and 4.0.1, pure-PHP X25519 scalar multiplication in phpseclib/Math/PrimeField/Integer.php performs data-dependent conditional modular reductions in add and subtract. During the Montgomery ladder in...

UBUNTU-CVE-2026-84308

phpseclib is a PHP secure communications library. Prior to 3.0.57 and 4.0.1, pure-PHP X25519 scalar multiplication in phpseclib/Math/PrimeField/Integer.php performs data-dependent conditional modular reductions in add and subtract. During the Montgomery ladder in...

CVE-2026-84308 phpseclib — non-constant-time X25519 scalar multiplication permits full private-key recovery

phpseclib is a PHP secure communications library. Prior to 3.0.57 and 4.0.1, pure-PHP X25519 scalar multiplication in phpseclib/Math/PrimeField/Integer.php performs data-dependent conditional modular reductions in add and subtract. During the Montgomery ladder in...

CVE-2026-84308 phpseclib — non-constant-time X25519 scalar multiplication permits full private-key recovery

phpseclib is a PHP secure communications library. Prior to 3.0.57 and 4.0.1, pure-PHP X25519 scalar multiplication in phpseclib/Math/PrimeField/Integer.php performs data-dependent conditional modular reductions in add and subtract. During the Montgomery ladder in...

CVE-2026-84308

phpseclib is a PHP secure communications library. Prior to 3.0.57 and 4.0.1, pure-PHP X25519 scalar multiplication in phpseclib/Math/PrimeField/Integer.php performs data-dependent conditional modular reductions in add and subtract. During the Montgomery ladder in...

CVE-2026-84308 phpseclib — non-constant-time X25519 scalar multiplication permits full private-key recovery

phpseclib is a PHP secure communications library. Prior to 3.0.57 and 4.0.1, pure-PHP X25519 scalar multiplication in phpseclib/Math/PrimeField/Integer.php performs data-dependent conditional modular reductions in add and subtract. During the Montgomery ladder in...

CVE-2026-84308

phpseclib , a PHP secure communications library, has a non-constant-time X25519 scalar multiplication flaw in versions prior to 3.0.57 and 4.0.1 . The root cause is data-dependent conditional modular reductions in the pure-PHP implementation (Math/PrimeField/Integer.php), which leak per-step timi...