CVE-2026-103321

HIGHPre-NVD 8.38.3—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4% (27th percentile of EPSS-scored CVEs). 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
Trending — 4 sources updated this week
8.3EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 8.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

MISP contains a stored cross-site script (XSS) vulnerability in the event graph preview feature.

The event graph preview image field was accepted and stored without server-side validation. On the client side, the stored value was rendered into an HTML img element's src attribute via string concatenation, allowing a crafted value to break out of the attribute context and inject arbitrary script.

Preconditions:

  • An authenticated MISP user with the ability to create or modify an event graph entry.
  • A second user (the victim) who views the event graph and triggers the preview popover.

Impact:

  • Execution of arbitrary JavaScript in the victim's browser within the MISP application context.
  • Potential theft of session tokens, cookies, or sensitive data accessible to the victim's browser.
  • Potential for performing actions on behalf of the victim within the MISP application.

Affected: MISP versions prior to the fix (commit applied after v2.5.48).

CVSS v3
8.3
EG Score
8.3HIGHmedium confidence
EG Risk
42
EG Risk 42/100CISA SSVC

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
Severity83% × 45%
Exploitation0% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.4%
EPSS %ILE
27th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track or Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 30, 2026

Last Modified

September 30, 2026

Advisory Details (1)

Auto-updated Sep 30, 2026
Patch available. Sources: github_commit.
github_commit Patch Available

commit 92c7ccc43 (MISP/MISP)

Patch available: MISP/MISP v2.5.48 (contains commit 92c7ccc43)

https://github.com/MISP/MISP/commit/92c7ccc43

Vendor Advisories for CVE-2026-103321(1)

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

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 16× in last 7d / 16× 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. 2026-10-04 10:59 UTCGHSA enrichment
  2. 2026-10-03 23:20 UTCEG score recompute
  3. 2026-10-03 23:20 UTCGHSA enrichment
  4. 2026-10-03 14:25 UTCEPSS rescore
  5. 2026-10-03 11:39 UTCGHSA enrichment
  6. 2026-10-02 23:42 UTCEG score recompute
  7. 2026-10-02 23:41 UTCGHSA enrichment
  8. 2026-10-02 12:01 UTCGHSA enrichment
  9. 2026-10-02 00:19 UTCEG score recompute
  10. 2026-10-02 00:19 UTCGHSA enrichment
  11. 2026-10-01 19:49 UTCEPSS rescore
  12. 2026-10-01 12:40 UTCGHSA enrichment
  13. 2026-10-01 01:01 UTCGHSA enrichment
  14. 2026-09-30 13:23 UTCEG score recompute
  15. 2026-09-30 12:28 UTCEG score recompute
  16. 2026-09-30 12:27 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-103321?
CVE-2026-103321 is a high vulnerability published on September 30, 2026. MISP contains a stored cross-site script (XSS) vulnerability in the event graph preview feature. The event graph preview image field was accepted and stored without server-side validation. On the client side, the stored value was rendered into an HTML img element's src attribute via string…
When was CVE-2026-103321 disclosed?
CVE-2026-103321 was first published on September 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-103321 actively exploited?
CVE-2026-103321 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (27th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-103321?
CVE-2026-103321 has a CVSS base score of 8.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-103321?
A fix for CVE-2026-103321 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-103321 are linked in the Vendor Advisories panel on this page.

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