8.6

CVE-2026-45077: sensiolabs symfony Deserialization of Untrusted Data

CVSS: 8.6v3.1HighAnalyzed
AliasesUBUNTU-CVE-2026-45077DEBIAN-CVE-2026-45077
Published 14-07-2026Last modified 14-07-2026
Open JSON

Vulnerability summary

CVE-2026-45077 is a high (CVSS 8.6) Deserialization of Untrusted Data vulnerability in sensiolabs symfony. EPSS estimates a 0.67% chance of exploitation in the next 30 days, higher than 50.9% of scored vulnerabilities.

Overall risk
35/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.6/10
010
High · v3.1 (NVD)
EPSS score
0.67%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 14-07-2026
    PublishedVulnerability first disclosed.
  2. 14-07-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

6 scores · 4 sources · 2 versions

EPSS trend

Probability

0.67%

Chance of exploitation in the next 30 days

Percentile

51%

Versus all other CVEs

30-day change

0.00 pp

From 0.67% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.67%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Symfony2 products
  • monolog-bridge< 5.4.52 | ≥ 6.0.0-BETA1, < 6.4.40 | ≥ 7.0.0-BETA1, < 7.4.12 | ≥ 8.0.0-BETA1, < 8.0.12
  • symfony< 5.4.52 | ≥ 6.0.0-BETA1, < 6.4.40 | ≥ 7.0.0-BETA1, < 7.4.12 | ≥ 8.0.0-BETA1, < 8.0.12
Debian1 product
  • symfony< 5.4.53+dfsg-0+deb12u1 | < 6.4.41+dfsg-0+deb13u1 | < 7.4.12+dfsg-1
Sensiolabs1 product
  • symfony< 5.4.52 | ≥ 6.0.0, < 6.4.40 | ≥ 7.0.0, < 7.4.12 | ≥ 8.0.0, < 8.0.12
Ubuntu1 product
  • symfonyAll versions (No fix recorded)

4 vendors · 5 products

References

10 links