HOMEVULNERABILITIESCVE-2026-45304
HIGH

CVE-2026-45304

CWE-776Published: July 14, 2026· Updated: Jul 15, 2026

7.5
CVSS v3.1
EPSS:0.76%probability of exploitation in 30 daysPercentile:51.1th

Official 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.

NVD Source

Technical Analysis

CVE-2026-45304 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

sensiolabs1 product(s)
symfony
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://github.com/symfony/symfony/commit/e77391b2e4f18821198f010d573674c8ed4a970a
PATCHhttps://github.com/symfony/symfony/security/advisories/GHSA-4qpc-3hr4-r2p4

All References (6)

→
https://github.com/symfony/symfony/commit/e77391b2e4f18821198f010d573674c8ed4a970aPatch
→
https://github.com/symfony/symfony/releases/tag/v5.4.52Product · Release Notes
→
https://github.com/symfony/symfony/releases/tag/v6.4.40Product · Release Notes
→
https://github.com/symfony/symfony/releases/tag/v7.4.12Product · Release Notes
→
https://github.com/symfony/symfony/releases/tag/v8.0.12Product · Release Notes
→
https://github.com/symfony/symfony/security/advisories/GHSA-4qpc-3hr4-r2p4Patch · Vendor Advisory

Quick Facts

CVE IDCVE-2026-45304
CVSS Score7.5 / 10
SeverityHIGH
WeaknessCWE-776
CISA KEVNo
EPSS (30d)0.76%
Affected1 vendor(s)
PublishedJul 14, 2026

Related CVEs (CWE-776)

CVE-2013-4335
9.8
CVE-2014-2228
9.8
CVE-2019-19144
9.8
CVE-2021-23926
9.1
CVE-2020-24590
9.1
CVE-2024-28982
8.2

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2026-45304 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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