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OpenAdvisories
High USN-8769-1 5 CVEs

phpseclib vulnerability

Published Sep 15, 2026 · Updated Sep 16, 2026

Ecosystem: Ubuntu

Summary

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.

Fixed packages 6

ReleasePackageFixed in
Ubuntu · 22.04 LTS 22.04:LTS phpseclib 1.0.20-1+deb12u3build0.22.04.1
Ubuntu · Pro 16.04 LTS Pro:16.04:LTS phpseclib 1.0.1-3ubuntu0.1+esm1
Ubuntu · Pro 18.04 LTS Pro:18.04:LTS phpseclib 1.0.9-1ubuntu0.1~esm2
Ubuntu · Pro 20.04 LTS Pro:20.04:LTS phpseclib 1.0.18-2ubuntu0.1~esm2
Ubuntu · Pro 24.04 LTS Pro:24.04:LTS phpseclib 1.0.23-1ubuntu0.1~esm1
Ubuntu · Pro 26.04 LTS Pro:26.04:LTS phpseclib 1.0.24-1ubuntu0.1~esm1

Vulnerabilities 5

  • High 8.2
    CVE-2026-32935

    phpseclib's AES-CBC unpadding susceptible to padding oracle timing attack

    phpseclib is a PHP secure communications library. Projects using versions 0.1.1 through 1.0.26, 2.0.0 through 2.0.51, and 3.0.0 through 3.0.49 are vulnerable to a to padding oracle timing attack when using AES in CBC mode. This issue has been fixed in version…

    phpseclib phpseclib nextcloud-server-33 php-phpseclib3 Debian Ubuntu Wolfi Packagist
  • High 7.5
    CVE-2023-52892

    Name confusion in x509 Subject Alternative Name fields

    In phpseclib before 1.0.22, 2.x before 2.0.46, and 3.x before 3.0.33, some characters in Subject Alternative Name fields in TLS certificates are incorrectly allowed to have a special meaning in regular expressions (such as a + wildcard), leading to name confu…

    php-phpseclib3 phpseclib/phpseclib phpseclib php-phpseclib Debian Ubuntu Packagist
  • High 7.5
    CVE-2024-27354

    phpseclib: guardrails needed on isPrime and randomPrime

    An issue was discovered in phpseclib 1.x before 1.0.23, 2.x before 2.0.47, and 3.x before 3.0.36. An attacker can construct a malformed certificate containing an extremely large prime to cause a denial of service (CPU consumption for an isPrime primality chec…

    php-phpseclib3 phpseclib/phpseclib phpseclib php-phpseclib Debian Ubuntu Packagist
  • High 7.5
    CVE-2024-27355

    phpseclib guardrails needed on OID length

    An issue was discovered in phpseclib 1.x before 1.0.23, 2.x before 2.0.47, and 3.x before 3.0.36. When processing the ASN.1 object identifier of a certificate, a sub identifier may be provided that leads to a denial of service (CPU consumption for decodeOID).

    php-phpseclib3 phpseclib/phpseclib php-phpseclib3 phpseclib Debian Ubuntu Packagist
  • Medium 5.9
    CVE-2023-48795 Public exploit Scanner template EPSS 94%

    Prefix Truncation Attack against ChaCha20-Poly1305 and Encrypt-then-MAC aka Terrapin

    The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypass integrity checks such that some packets are omitted (from the extension negotiation message), and a client and server…

    zot kubescape kots k3d Debian Ubuntu Azure Linux Alpine Wolfi PyPI Go crates.io

References

  • report
    https://ubuntu.com/security/CVE-2023-48795
  • report
    https://ubuntu.com/security/CVE-2023-52892
  • report
    https://ubuntu.com/security/CVE-2024-27354
  • report
    https://ubuntu.com/security/CVE-2024-27355
  • report
    https://ubuntu.com/security/CVE-2026-32935