CVE-2026-13323

HIGHNVD 8.74.1▼
EchelonGraph scoreMEDIUM confidence

Score 4.1 from GitHub Security Advisory published 2026-07-01. NVD baseline CVSS 8.7; sources differ by 4.6.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 4 sources updated this week
8.7
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 8.7Exploit: NoneExposed: 0

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

In Open VSX Registry before 1.0.2, the /vscode/unpkg/ endpoint serves user-supplied HTML files with Content-Type: text/html and without a Content-Security-Policy or Content-Disposition: attachment response header. An unauthenticated attacker can register a publisher account, upload a VSIX containing a crafted HTML payload, and induce an authenticated user to visit the resulting URL. The browser renders the file inline in the open-vsx.org origin context, enabling session token exfiltration, persistent Personal Access Token (PAT) generation, and unauthorized publication of malicious extension versions. Because Open VSX extensions are distributed to VS Code, VSCodium, Cursor, Windsurf, and compatible editors, a compromised extension update constitutes a supply chain attack against all downstream users.

CVSS v3
8.7
EG Score
4.1(medium)
EPSS
6.6%
KEV
Not listed

Published

July 1, 2026

Last Modified

July 6, 2026

Advisory Details (2)

Auto-updated Jul 3, 2026
🔬 Proof of concept available. Patch available. Sources: github_pr.
generic🟡 PoC Available

Stored XSS on Open VSX Registry Leading to Publisher Account Takeover (#485) · Issues · Eclipse Projects Security / vulnerability-reports · GitLab

https://gitlab.eclipse.org/security/vulnerability-reports/-/work_items/485
github_pr Patch Available

Fix: add consistent and strict http headers when serving files inside extensions

Patch available: eclipse-openvsx/openvsx cli-1.0.2 (PR #1922 merged 2026-06-23)

https://github.com/eclipse-openvsx/openvsx/pull/1922

Vendor Advisories for CVE-2026-13323(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 19× in last 7d / 19× 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 02:03 UTCEG score recompute
  2. 2026-07-07 02:02 UTCGHSA enrichment
  3. 2026-07-06 21:35 UTCNVD updateCVSS v3 → 8.7 · severity → HIGH
  4. 2026-07-06 16:27 UTCEPSS rescore
  5. 2026-07-06 03:49 UTCEG score recompute
  6. 2026-07-06 03:49 UTCGHSA enrichment
  7. 2026-07-05 05:38 UTCEG score recompute
  8. 2026-07-05 05:38 UTCGHSA enrichment
  9. 2026-07-05 02:30 UTCEPSS rescore
  10. 2026-07-05 02:30 UTCEPSS rescore
  11. 2026-07-04 07:26 UTCEG score recompute
  12. 2026-07-04 07:26 UTCGHSA enrichment
  13. 2026-07-04 06:31 UTCEPSS rescore
  14. 2026-07-03 09:09 UTCEG score recompute
  15. 2026-07-03 09:09 UTCGHSA enrichment
  16. 2026-07-02 10:59 UTCEG score recompute
  17. 2026-07-02 10:59 UTCGHSA enrichment
  18. 2026-07-01 12:47 UTCEG score recompute
  19. 2026-07-01 12:47 UTCGHSA enrichment

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-13323?
CVE-2026-13323 is a high vulnerability published on July 1, 2026. In Open VSX Registry before 1.0.2, the /vscode/unpkg/ endpoint serves user-supplied HTML files with Content-Type: text/html and without a Content-Security-Policy or Content-Disposition: attachment response header. An unauthenticated attacker can register a publisher account, upload a VSIX…
When was CVE-2026-13323 disclosed?
CVE-2026-13323 was first published in the National Vulnerability Database on July 1, 2026, with the most recent update on July 6, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-13323 actively exploited?
CVE-2026-13323 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 6.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-13323?
CVE-2026-13323 has a CVSS v3 base score of 8.7 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 4.1.
How do I remediate CVE-2026-13323?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-13323, 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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