PT-2026-44145 · Symfony · Monolog-Bridge+1

Published 2026-05-21 · Updated 2026-05-28 · CVE-2026-45077

Positive Technologies (AI Summary)

CVSS v4.0

8.1

High

Base vector

AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U

Name of the Vulnerable Software and Affected Versions symfony/monolog-bridge versions prior to 5.4.52 symfony/monolog-bridge versions prior to 6.4.40 symfony/monolog-bridge versions prior to 7.4.12 symfony/monolog-bridge versions prior to 8.0.12 symfony/symfony versions prior to 5.4.52 symfony/symfony versions prior to 6.4.40 symfony/symfony versions prior to 7.4.12 symfony/symfony versions prior to 8.0.12

Description The server:log console command, implemented in SymfonyBridgeMonologCommandServerLogCommand, contains a PHP object deserialization flaw. By default, the listener binds to 0.0.0.0:9911, making it accessible on all network interfaces. The command processes incoming messages using unserialize(base64 decode($message)) without authentication, integrity checks, or a class allowlist. This allows remote attackers to send malicious serialized PHP objects. Depending on the available gadget chains in the target environment, this can lead to remote code execution or a denial of service, as sending a non-array object crashes the listener with a type error.

Recommendations Update symfony/monolog-bridge to version 5.4.52 or newer. Update symfony/monolog-bridge to version 6.4.40 or newer. Update symfony/monolog-bridge to version 7.4.12 or newer. Update symfony/monolog-bridge to version 8.0.12 or newer. Update symfony/symfony to version 5.4.52 or newer. Update symfony/symfony to version 6.4.40 or newer. Update symfony/symfony to version 7.4.12 or newer. Update symfony/symfony to version 8.0.12 or newer. As a temporary mitigation, restrict access to TCP port 9911 or avoid running the server:log command on interfaces exposed to untrusted networks.

Exploit

Fix

Deserialization of Untrusted Data

Exposure of Resource to Wrong Sphere

Weakness Enumeration

CWE-502

CWE-668

Related Identifiers

CVE-2026-45077

GHSA-M7V2-7GXM-VC2V

Affected Products

Monolog-Bridge

Symfony

References · 14

• 🔥 https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2026-45077.yaml · Exploit
• 🔥 https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/monolog-bridge/CVE-2026-45077.yaml · Exploit
• https://ubuntu.com/security/CVE-2026-45077 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-45077 · Vendor Advisory
• https://osv.dev/vulnerability/GHSA-m7v2-7gxm-vc2v · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-45077 · Security Note
• https://security-tracker.debian.org/tracker/CVE-2026-45077 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-45077 · Vendor Advisory
• https://github.com/symfony/symfony/security/advisories/GHSA-m7v2-7gxm-vc2v · Note
• https://github.com/symfony/symfony · Note
• https://github.com/symfony/symfony/commit/0891b2f293896c488e26943dc034334364b77fc4 · Note
• https://symfony.com/cve-2026-45077 · Note
• https://twitter.com/UpwindMDR/status/2059884216611913931 · Twitter Post
• https://symfony.com/blog/cve-2026-45077-unauthenticated-php-object-deserialization-in-monologbridge-server-log-listener · Note