CVE-2026-45305

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.8%, top 49% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 7.5Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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::cleanup() used regular expressions with overlapping quantifiers for YAML directive, comment, and document marker cleanup, allowing crafted input to make parsing hang for an arbitrarily long time. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation1% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
51.1%
KEV
Not listed

Published

May 27, 2026

Last Modified

July 15, 2026

Advisory Details (6)

Auto-updated Jul 14, 2026
Patch available. Sources: github_release, github, github_commit.
github Patch Available

YAML Parser ReDoS via Catastrophic Backtracking in Parser::cleanup() Regex · Advisory · symfony/symfony · GitHub

https://github.com/symfony/symfony/security/advisories/GHSA-9frc-8383-795m
github_release Patch Available

v8.0.12

Patch available: symfony/symfony v8.0.12

https://github.com/symfony/symfony/releases/tag/v8.0.12
github_release Patch Available

v7.4.12

Patch available: symfony/symfony v7.4.12

https://github.com/symfony/symfony/releases/tag/v7.4.12
github_release Patch Available

v6.4.40

Patch available: symfony/symfony v6.4.40

https://github.com/symfony/symfony/releases/tag/v6.4.40
github_release Patch Available

v5.4.52

Patch available: symfony/symfony v5.4.52

https://github.com/symfony/symfony/releases/tag/v5.4.52
github_commit Patch Available

commit 9749cd43c5e0 (symfony/symfony)

Patch available: symfony/symfony v5.4.52 (contains commit 9749cd43c5e0)

https://github.com/symfony/symfony/commit/9749cd43c5e09b3735093623670b21b9d8a056cb

Vendor Advisories for CVE-2026-45305(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(2 across 1 ecosystem)
Packagist(2)
PackageVulnerable rangeFixed inDependents
symfony/symfonyv8.0.0 ... v8.0.9 (12 versions)8.0.12—
symfony/yamlv8.0.0 ... v8.0.8 (6 versions)8.0.12—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 12× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-23 03:16 UTCEG score recompute▼ 1.20
  2. 2026-07-22 14:08 UTCEPSS rescore
  3. 2026-07-21 15:24 UTCEPSS rescore
  4. 2026-07-20 17:08 UTCEPSS rescore
  5. 2026-07-19 14:31 UTCEPSS rescore
  6. 2026-07-19 02:29 UTCEPSS rescore
  7. 2026-07-18 10:04 UTCEPSS rescore
  8. 2026-07-16 17:03 UTCEPSS rescore
  9. 2026-07-15 16:57 UTCEPSS rescore
  10. 2026-07-15 16:23 UTCNVD updateCVSS v3 → 7.5
  11. 2026-07-14 19:03 UTCEG score recompute▲ 8.70
  12. 2026-07-14 19:00 UTCMITRE cvelistV5CVSS v3 → 8.7 · CVSS v4 → 8.7 · severity → HIGH
  13. 2026-06-14 23:18 UTCEPSS rescore
  14. 2026-06-13 23:00 UTCEPSS rescore
  15. 2026-06-12 23:12 UTCEPSS rescore
  16. 2026-05-27 21:35 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-45305?
CVE-2026-45305 is a high vulnerability published on May 27, 2026. 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::cleanup() used regular expressions with overlapping quantifiers for YAML directive, comment, and document marker cleanup,…
When was CVE-2026-45305 disclosed?
CVE-2026-45305 was first published in the National Vulnerability Database on May 27, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-45305 actively exploited?
CVE-2026-45305 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 51.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-45305?
CVE-2026-45305 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-45305?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-45305, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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