CVE-2026-45077 json
Symfony: Unauthenticated PHP Object Deserialization in MonologBridge server:log Listener
published 2026-05-27 5 mo ago modified 2026-09-10 1 mo ago also GHSA-m7v2-7gxm-vc2v , EUVD-2026-44330
- cvss
- 8.6
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.7%
- EPSS 0.7% chance of exploitation in 30 days, percentile 52%
- public exploits
- 0
- none known
Summary
Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12, the server:log listener (Symfony\Bridge\Monolog\Command\ServerLogCommand) binds to 0.0.0.0:9911 by default and processes each received frame with unserialize(base64_decode($message)) without authentication, integrity checks, or an allowed_classes allowlist, allowing any reachable host to submit attacker-chosen serialized PHP payloads that can crash the listener and may trigger object-injection gadget effects. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.
Patch / fix
- packagist symfony/monolog-bridge 5.4.52, 6.4.40, 7.4.12, 8.0.12
- packagist symfony/symfony 5.4.52, 6.4.40, 7.4.12, 8.0.12
- sensiolabs symfony 5.4.52, 6.4.40, 7.4.12, 8.0.12
- symfony Debian 12 5.4.53+dfsg-0+deb12u1
- symfony Debian 13 6.4.41+dfsg-0+deb13u1
- symfony Debian 14 7.4.12+dfsg-1
debian advisories DEBIAN-CVE-2026-45077
- github.com/symfony/symfony@0891b2f commit
- github.com/symfony/symfony/releases/tag/v5.4.52 release
- github.com/symfony/symfony/releases/tag/v6.4.40 release
- github.com/symfony/symfony/releases/tag/v7.4.12 release
- github.com/symfony/symfony/releases/tag/v8.0.12 release
- github.com/symfony/symfony/security/advisories/GHSA-m7v2-7gxm-vc2v advisory
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 3 mo ago
Exploit prediction
0.67% chance of exploitation in the next 30 days, higher than 52% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 8.3 | 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 | 4.0 | 8.3 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| NVD | 3.1 | 8.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| packagist | symfony/monolog-bridge | <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 |
| packagist | symfony/symfony | <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 |
Affected products
- symfony symfony
- symfony monolog-bridge
Classification
References
-
github.com
/symfony/symfony/commit/0891b2f293896c488e26943dc034334364b77fc4
web, patch
-
github.com
/symfony/symfony/security/advisories/GHSA-m7v2-7gxm-vc2v
web, patch, vendor-advisory
-
github.com
/symfony/symfony/releases/tag/v5.4.52
product, release-notes
-
github.com
/symfony/symfony/releases/tag/v6.4.40
product, release-notes
-
github.com
/symfony/symfony/releases/tag/v7.4.12
product, release-notes
-
github.com
/symfony/symfony/releases/tag/v8.0.12
product, release-notes
-
github.com
/FriendsOfPHP/security-advisories/blob/master/symfony/monolog-bridge/CVE-2026-45077.yaml
web
-
github.com
/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2026-45077.yaml
web
-
github.com
/symfony/symfony
package
-
symfony.com
/cve-2026-45077
web
Sources
- CVE List CVE-2026-45077
- GitHub Advisory GHSA-m7v2-7gxm-vc2v
- NVD CVE-2026-45077
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