CVE-2026-55691

HIGHPre-NVD 8.68.6
EchelonGraph scoreLOW confidence

This high-severity CVE scores 8.6 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). 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
8.6
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: —CVSS: 8.6Exploit: NoneExposed: 0

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

StarCitizenWiki Extension Embed Video: Stored XSS via unsanitized class passed to template

Summary

The user supplied class value is fed directly into the sprintf call that creates HTML. You can add a quote to escape the class and then inject arbitrary html/javascript to the final output.

Details

The template here adds a figure with a class that is substituted in. This value is provided to sprintf here, an unescaped version of the class supplied by the user.

$template = <<
        %s%s%s%s
    
HTML;

PoC

Note the double quote immediately following the single quote to escape the class attribute in the template: 
dQw4w9WgXcQ

Impact

Arbitrary HTML can be inserted into the DOM by any user on any page, allowing for JavaScript to be executed.

CVSS v3
8.6
EG Score
8.6(low)
EPSS
—
KEV
Not listed

Published

June 19, 2026

Last Modified

June 19, 2026

Vendor Advisories for CVE-2026-55691(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
starcitizenwiki/embedvideo3.0.0 ... 4.0.0 (26 versions)4.1.0—

Data Freshness Timeline

(refreshed 14× in last 7d / 35× 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. 2026-07-07 01:44 UTCEG score recompute
  2. 2026-07-06 13:38 UTCEG score recompute
  3. 2026-07-06 01:27 UTCEG score recompute
  4. 2026-07-05 13:22 UTCEG score recompute
  5. 2026-07-05 01:17 UTCEG score recompute
  6. 2026-07-04 13:12 UTCEG score recompute
  7. 2026-07-04 01:06 UTCEG score recompute
  8. 2026-07-03 12:59 UTCEG score recompute
  9. 2026-07-03 00:44 UTCEG score recompute
  10. 2026-07-02 12:38 UTCEG score recompute
  11. 2026-07-02 00:30 UTCEG score recompute
  12. 2026-07-01 12:18 UTCEG score recompute
  13. 2026-07-01 00:08 UTCEG score recompute
  14. 2026-06-30 11:55 UTCEG score recompute
  15. 2026-06-29 23:50 UTCEG score recompute
  16. 2026-06-29 11:45 UTCEG score recompute
  17. 2026-06-28 23:40 UTCEG score recompute
  18. 2026-06-28 11:34 UTCEG score recompute
  19. 2026-06-27 23:29 UTCEG score recompute
  20. 2026-06-27 11:24 UTCEG score recompute
  21. 2026-06-26 23:17 UTCEG score recompute
  22. 2026-06-26 11:13 UTCEG score recompute
  23. 2026-06-25 22:47 UTCEG score recompute
  24. 2026-06-25 10:42 UTCEG score recompute
  25. 2026-06-24 22:37 UTCEG score recompute
Show 10 more
  1. 2026-06-24 10:32 UTCEG score recompute
  2. 2026-06-23 22:24 UTCEG score recompute
  3. 2026-06-23 10:19 UTCEG score recompute
  4. 2026-06-22 22:13 UTCEG score recompute
  5. 2026-06-22 10:07 UTCEG score recompute
  6. 2026-06-21 21:50 UTCEG score recompute
  7. 2026-06-21 09:42 UTCEG score recompute
  8. 2026-06-20 21:36 UTCEG score recompute
  9. 2026-06-20 09:31 UTCEG score recompute
  10. 2026-06-19 21:23 UTCEG score recompute

Frequently asked(4)

What is CVE-2026-55691?
CVE-2026-55691 is a high vulnerability published on June 19, 2026. StarCitizenWiki Extension Embed Video: Stored XSS via unsanitized class passed to template Summary The user supplied class value is fed directly into the sprintf call that creates HTML. You can add a quote to escape the class and then inject arbitrary html/javascript to the final output. Details…
When was CVE-2026-55691 disclosed?
CVE-2026-55691 was first published in the National Vulnerability Database on June 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-55691?
CVE-2026-55691 has a CVSS v4.0 base score of 8.6 (CNA self-assessment; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-55691?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55691, 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-2026-55691

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