CVE-2026-88921

MEDIUMPre-NVD 5.15.1—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 70% 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
Trending — 3 sources updated this week
5.1EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.1Exploit: None knownExposed: 0

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

MISP contains an HTML injection vulnerability in the MISPElementHTMLFormatterTool component, which is responsible for rendering MISP element references (attributes, objects, and tags) into inline HTML during PDF report export via the convert_markdown_to_pdf module. The attribute(), objectAttribute(), object(), and tag() methods interpolated user-controlled fields (attribute type, attribute value, object name, object relation, tag name, tag colour, and tag text colour) directly into HTML templates without applying HTML entity encoding. An authenticated user with the ability to create or modify MISP attributes, objects, or tags could embed arbitrary HTML markup in these fields. When a report containing such elements was exported to PDF, the unescaped content was rendered as live HTML rather than inert text, potentially injecting script tags, breaking the document structure, or altering the visual content of the exported report. Additionally, the attribute() method contained a template with hardcoded sample values ("domain-ip" and "google.com") instead of format placeholders, meaning every plain attribute reference in a PDF displayed the sample text rather than the actual indicator value, constituting a data-integrity defect in the exported document. The vulnerability requires an authenticated actor with write access to MISP elements and a subsequent PDF export of a report referencing those elements. The security impact is primarily to the integrity of the exported document and, depending on the HTML-to-PDF rendering engine, potential execution of injected markup during the conversion step.

Version affected: ≤2.5.45

CVSS v3
5.1
EG Score
5.1(medium)
EG Risk
23(Track)
EG Risk 23/100SSVC: 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
Severity51% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
30%
KEV
Not listed

Published

September 10, 2026

Last Modified

September 10, 2026

Advisory Details (1)

Auto-updated Sep 10, 2026
Patch available. Sources: github_commit.
github_commit Patch Available

commit 949744a4b (MISP/MISP)

Patch available: MISP/MISP v2.5.46 (contains commit 949744a4b)

https://github.com/MISP/MISP/commit/949744a4b

Vendor Advisories for CVE-2026-88921(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 19× in last 7d / 33× 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. 2026-09-19 20:21 UTCEG score recompute
  2. 2026-09-19 20:21 UTCGHSA enrichment
  3. 2026-09-18 20:06 UTCEG score recompute
  4. 2026-09-18 20:06 UTCGHSA enrichment
  5. 2026-09-18 19:28 UTCEPSS rescore
  6. 2026-09-17 19:50 UTCEG score recompute
  7. 2026-09-17 19:50 UTCGHSA enrichment
  8. 2026-09-17 19:32 UTCEPSS rescore
  9. 2026-09-16 18:54 UTCEG score recompute
  10. 2026-09-16 18:54 UTCGHSA enrichment
  11. 2026-09-16 14:09 UTCEPSS rescore
  12. 2026-09-16 05:15 UTCEPSS rescore
  13. 2026-09-15 18:37 UTCEG score recompute
  14. 2026-09-15 18:37 UTCGHSA enrichment
  15. 2026-09-15 03:12 UTCEPSS rescore
  16. 2026-09-14 18:19 UTCGHSA enrichment
  17. 2026-09-13 18:04 UTCEG score recompute
  18. 2026-09-13 18:04 UTCGHSA enrichment
  19. 2026-09-13 16:48 UTCEPSS rescore
  20. 2026-09-12 17:49 UTCEG score recompute
  21. 2026-09-12 17:49 UTCGHSA enrichment
  22. 2026-09-12 15:02 UTCEPSS rescore
  23. 2026-09-11 17:35 UTCEG score recompute
  24. 2026-09-11 17:35 UTCGHSA enrichment
  25. 2026-09-11 14:53 UTCEPSS rescore
Show 8 more
  1. 2026-09-11 14:53 UTCEPSS rescore
  2. 2026-09-10 17:20 UTCEG score recompute
  3. 2026-09-10 17:20 UTCGHSA enrichment
  4. 2026-09-10 17:14 UTCEG score recompute
  5. 2026-09-10 17:13 UTCGHSA enrichment
  6. 2026-09-10 14:19 UTCEG score recompute
  7. 2026-09-10 13:45 UTCEG score recompute
  8. 2026-09-10 13:44 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-88921?
CVE-2026-88921 is a medium vulnerability published on September 10, 2026. MISP contains an HTML injection vulnerability in the MISPElementHTMLFormatterTool component, which is responsible for rendering MISP element references (attributes, objects, and tags) into inline HTML during PDF report export via the convertmarkdownto_pdf module. The attribute(), objectAttribute(),…
When was CVE-2026-88921 disclosed?
CVE-2026-88921 was first published in the National Vulnerability Database on September 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-88921 actively exploited?
CVE-2026-88921 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 70.4% of all scored CVEs.
What is the CVSS score of CVE-2026-88921?
CVE-2026-88921 has a CVSS v3 base score of 5.1 (NVD).
How do I remediate CVE-2026-88921?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-88921, 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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