GHSA-m7v2-7gxm-vc2v: symfony/monolog-bridge (CVE-2026-45077)

Package	Ecosystem	Affected	Fixed in
symfony/monolog-bridge	Packagist	<5.4.52 \|\| >=6.0.0, <6.4.40 \|\| >=7.0.0, <7.4.12 \|\| >=8.0.0, <8.0.12	5.4.52, 6.4.40, 7.4.12, 8.0.12
symfony/symfony	Packagist	<5.4.52 \|\| >=6.0.0, <6.4.40 \|\| >=7.0.0, <7.4.12 \|\| >=8.0.0, <8.0.12	5.4.52, 6.4.40, 7.4.12, 8.0.12

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Symfony's symfony/monolog-bridge and symfony/symfony packages are affected in versions before 5.4.52, from 6.0.0 before 6.4.40, from 7.0.0 before 7.4.12, and from 8.0.0 before 8.0.12. The server:log console command listens on all interfaces by default and unserializes incoming messages without authentication or class restrictions, so anyone who can reach TCP port 9911 can cause a denial of service and may be able to trigger object injection. Upgrade to 5.4.52, 6.4.40, 7.4.12, or 8.0.12, which bind to 127.0.0.1 by default and restrict deserializable classes.

Written 31 Oct 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
8.3	High	4.0	CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N	CNA (GitHub_M)

CISA KEV Not listed.
EPSS 0.0067, the 52nd percentile, on 11 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

20 May 2026, 10:21 UTC Published by the maintainers as a GitHub repository advisory
31 Oct 2026, 13:58 UTC First seen by agentprime
31 Oct 2026, 13:58 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.