CVE-2026-45066

MEDIUMNVD 6.12.3
EchelonGraph scoreLOW confidence

This low-severity CVE scores 2.3 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit probability: 0.0%, top 84% 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: cna:github_m, epss
Trending — 3 sources updated this week
6.1
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.1Exploit: 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. From 6.1.0-BETA1 until 6.4.40, 7.4.12, and 8.0.12, HtmlSanitizer URL sanitization can allow off-allowlist URLs through allowLinkHosts() or allowMediaHosts() because UrlSanitizer::parse() follows RFC 3986 while browsers follow WHATWG URL parsing, and because is checked against the media policy rather than the link policy. This issue is fixed in versions 6.4.40, 7.4.12, and 8.0.12.

CVSS v3
6.1
EG Score
2.3(low)
EG Risk
—
EPSS
21.1%
KEV
Not listed

Published

May 27, 2026

Last Modified

July 16, 2026

Advisory Details (5)

Auto-updated Jul 15, 2026
Patch available. Sources: github_release, github, github_commit.
github Patch Available

HtmlSanitizer allowLinkHosts() / allowMediaHosts() Bypass via URL-Parser Differentials and <area> Misclassification · Advisory · symfony/symfony · GitHub

https://github.com/symfony/symfony/security/advisories/GHSA-qc95-4862-92fh
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_commit

commit d506b556d3d3 (symfony/symfony)

Fix landed in symfony/symfony commit d506b556d3d3 — awaiting tagged release

https://github.com/symfony/symfony/commit/d506b556d3d3906f3e8660ad82257ce87edbaac4

Vendor Advisories for CVE-2026-45066(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/html-sanitizerv8.0.0, v8.0.7, v8.0.88.0.12—
symfony/symfonyv8.0.0 ... v8.0.9 (12 versions)8.0.12—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 13× 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. 2026-07-22 14:08 UTCEPSS rescore
  2. 2026-07-21 15:24 UTCEPSS rescore
  3. 2026-07-20 17:08 UTCEPSS rescore
  4. 2026-07-19 14:31 UTCEPSS rescore
  5. 2026-07-19 02:29 UTCEPSS rescore
  6. 2026-07-18 10:04 UTCEPSS rescore
  7. 2026-07-16 17:03 UTCEPSS rescore
  8. 2026-07-16 16:30 UTCNVD updateCVSS v3 → 6.1 · severity → MEDIUM
  9. 2026-07-16 14:44 UTCMITRE cvelistV5CVSS v3 → 2.3 · severity → LOW
  10. 2026-07-15 16:57 UTCEPSS rescore
  11. 2026-07-15 14:22 UTCNVD updateCVSS v3 → 6.1 · severity → MEDIUM
  12. 2026-07-14 18:07 UTCEG score recompute▲ 2.30
  13. 2026-07-14 18:05 UTCMITRE cvelistV5CVSS v3 → 2.3 · CVSS v4 → 2.3 · severity → LOW
  14. 2026-06-14 23:18 UTCEPSS rescore
  15. 2026-06-13 23:00 UTCEPSS rescore
  16. 2026-06-12 23:12 UTCEPSS rescore
  17. 2026-05-27 20:35 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-45066?
CVE-2026-45066 is a medium vulnerability published on May 27, 2026. Symfony is a PHP framework for web and console applications and a set of reusable PHP components. From 6.1.0-BETA1 until 6.4.40, 7.4.12, and 8.0.12, HtmlSanitizer URL sanitization can allow off-allowlist URLs through allowLinkHosts() or allowMediaHosts() because UrlSanitizer::parse() follows RFC…
When was CVE-2026-45066 disclosed?
CVE-2026-45066 was first published in the National Vulnerability Database on May 27, 2026, with the most recent update on July 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-45066 actively exploited?
CVE-2026-45066 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 21.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-45066?
CVE-2026-45066 has a CVSS v3 base score of 6.1 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 2.3. The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-45066?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-45066, 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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