CVE-2026-55877

MEDIUMPre-NVD 6.16.1—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 91% 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, secondary
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 UX is a JavaScript ecosystem for Symfony. From 2.17.0 before 2.36.1 and from 3.0.0 before 3.2.0, the ux_icon() Twig function is marked is_safe=['html'] and Icon::toHtml() inlines SVG source verbatim, allowing unsanitized local SVG files or Iconify on-demand JSON body responses containing nested script elements, on* event handlers, or dangerous URL schemes to execute cross-site scripting. This issue is fixed in versions 2.36.1 and 3.2.0.

CVSS v3
6.1
EG Score
6.1(medium)
EG Risk
28(Track)
EG Risk 28/100SSVC: 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
Severity61% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
9.3%
KEV
Not listed

Published

June 19, 2026

Last Modified

July 10, 2026

Advisory Details (4)

Auto-updated Jul 8, 2026
Patch available. Sources: github_commit, github_release, github.
github Patch Available

XSS in symfony/ux-icons via unsanitized SVG content in local files and Iconify on-demand responses · Advisory · symfony/ux · GitHub

https://github.com/symfony/ux/security/advisories/GHSA-6v8j-33hc-mv84
github_release Patch Available

v3.2.0

Patch available: symfony/ux v3.2.0

https://github.com/symfony/ux/releases/tag/v3.2.0
github_release Patch Available

v2.36.1

Patch available: symfony/ux v2.36.1

https://github.com/symfony/ux/releases/tag/v2.36.1
github_commit Patch Available

commit 3a4964ec3700 (symfony/ux)

Patch available: symfony/ux v2.36.1 (contains commit 3a4964ec3700)

https://github.com/symfony/ux/commit/3a4964ec3700f0af4e13f7bfbf8bb3174c3e79d1

Vendor Advisories for CVE-2026-55877(1)

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

Affected Packages

(1 across 1 ecosystem)
Packagist(1)
PackageVulnerable rangeFixed inDependents
symfony/ux-iconsv3.0.0, v3.1.03.2.0—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 22× 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 14:18 UTCEPSS rescore
  2. 2026-07-23 03:20 UTCEG score recompute
  3. 2026-07-22 14:08 UTCEPSS rescore
  4. 2026-07-21 15:25 UTCEPSS rescore
  5. 2026-07-20 17:08 UTCEPSS rescore
  6. 2026-07-19 14:31 UTCEPSS rescore
  7. 2026-07-19 14:31 UTCEPSS rescore
  8. 2026-07-19 02:29 UTCEPSS rescore
  9. 2026-07-18 10:04 UTCEPSS rescore
  10. 2026-07-16 17:03 UTCEPSS rescore
  11. 2026-07-15 16:57 UTCEPSS rescore
  12. 2026-07-15 16:57 UTCEPSS rescore
  13. 2026-07-15 02:00 UTCEPSS rescore
  14. 2026-07-15 02:00 UTCEPSS rescore
  15. 2026-07-13 22:31 UTCEPSS rescore
  16. 2026-07-13 06:13 UTCEPSS rescore
  17. 2026-07-13 06:13 UTCEPSS rescore
  18. 2026-07-12 05:46 UTCEPSS rescore
  19. 2026-07-11 08:27 UTCEPSS rescore
  20. 2026-07-11 08:27 UTCEPSS rescore
  21. 2026-07-09 19:10 UTCEPSS rescore
  22. 2026-07-09 19:10 UTCEPSS rescore
  23. 2026-06-19 22:24 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-55877?
CVE-2026-55877 is a medium vulnerability published on June 19, 2026. Symfony UX is a JavaScript ecosystem for Symfony. From 2.17.0 before 2.36.1 and from 3.0.0 before 3.2.0, the uxicon() Twig function is marked issafe=['html'] and Icon::toHtml() inlines SVG source verbatim, allowing unsanitized local SVG files or Iconify on-demand JSON body responses containing…
When was CVE-2026-55877 disclosed?
CVE-2026-55877 was first published in the National Vulnerability Database on June 19, 2026, with the most recent update on July 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55877 actively exploited?
CVE-2026-55877 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 9.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-55877?
CVE-2026-55877 has a CVSS v3 base score of 6.1 (NVD).
How do I remediate CVE-2026-55877?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55877, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-55877

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