8.7

CVE-2026-45304: sensiolabs symfony XML Entity Expansion

CVSS: 8.7v4.0HighAnalyzed
AliasesUBUNTU-CVE-2026-45304DEBIAN-CVE-2026-45304CGA-35xw-r7mm-9x8g
Published 14-07-2026Last modified 14-07-2026
Open JSON

Vulnerability summary

CVE-2026-45304 is a high (CVSS 8.7) XML Entity Expansion vulnerability in sensiolabs symfony. EPSS estimates a 0.68% chance of exploitation in the next 30 days, higher than 51.7% of scored vulnerabilities.

Overall risk
35/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.7/10
010
High · v4.0 (CVE.org)
EPSS score
0.68%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 0 · Related 1
CGA-R882-6FRC-5PH8

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, Symfony\Component\Yaml\Parser resolved YAML collection aliases recursively, allowing a small untrusted YAML input to expand into a multi-gigabyte structure and exhaust memory. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.

CVSS metrics

7 scores · 5 sources · 2 versions

EPSS trend

Probability

0.68%

Chance of exploitation in the next 30 days

Percentile

52%

Versus all other CVEs

30-day change

0.00 pp

From 0.68% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.68%

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

Chainguard2 products
  • zabbix-web-nginx-pgsql-fips-6.0< 6.0.45-r4
  • zabbix-web-nginx-pgsql-fips-7.0< 7.0.25-r1
Symfony2 products
  • 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
  • yaml< 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)

5 vendors · 7 products

References

12 links
Show all 12 references