CVE-2026-90990

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4% (34th 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 — 3 sources updated this week
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 5.3Exploit: None knownExposed services: Not assessed

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

Improper neutralization of newlines in filter values in the monitoring host and service list APIs in Checkmk <2.5.0p14 allows an authenticated user to inject additional Livestatus query headers, bypassing object visibility restrictions in count queries to infer information about hosts and services outside their contact groups and occupying web server and Livestatus workers for an attacker-controlled duration.

CVSS v3
5.3
EG Score
5.3MEDIUMmedium confidence
EG Risk
24
EG Risk 24/100CISA 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
Severity53% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.
EPSS PROB
0.4%
EPSS %ILE
34th
KEV
Not listed

CISA SSVCTrack at every mission impact level.

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). 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 22, 2026

Last Modified

September 22, 2026

Advisory Details (1)

Auto-updated Sep 22, 2026
No patch confirmed yet.
generic

Werk #19604: Fix Livestatus injection via monitoring filter values

https://checkmk.com/werk/19604

Vendor Advisories for CVE-2026-90990(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 18× in last 7d / 34× 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. 2026-10-03 18:48 UTCEG score recompute
  2. 2026-10-03 18:48 UTCGHSA enrichment
  3. 2026-10-02 17:47 UTCEG score recompute
  4. 2026-10-02 17:47 UTCGHSA enrichment
  5. 2026-10-01 19:51 UTCEPSS rescore
  6. 2026-10-01 17:28 UTCGHSA enrichment
  7. 2026-09-30 17:09 UTCEG score recompute
  8. 2026-09-30 17:09 UTCGHSA enrichment
  9. 2026-09-30 15:04 UTCEPSS rescore
  10. 2026-09-29 16:48 UTCEG score recompute
  11. 2026-09-29 16:48 UTCGHSA enrichment
  12. 2026-09-28 16:15 UTCEG score recompute
  13. 2026-09-28 16:15 UTCGHSA enrichment
  14. 2026-09-28 13:52 UTCEPSS rescore
  15. 2026-09-28 13:52 UTCEPSS rescore
  16. 2026-09-27 15:57 UTCEG score recompute
  17. 2026-09-27 15:57 UTCGHSA enrichment
  18. 2026-09-27 13:49 UTCEPSS rescore
  19. 2026-09-26 15:59 UTCEPSS rescore
  20. 2026-09-26 15:39 UTCEG score recompute
  21. 2026-09-26 15:39 UTCGHSA enrichment
  22. 2026-09-25 15:22 UTCGHSA enrichment
  23. 2026-09-24 15:03 UTCEG score recompute
  24. 2026-09-24 15:03 UTCGHSA enrichment
  25. 2026-09-24 14:04 UTCEPSS rescore
Show 9 more
  1. 2026-09-23 17:54 UTCEPSS rescore
  2. 2026-09-23 14:37 UTCGHSA enrichment
  3. 2026-09-22 14:20 UTCEG score recompute
  4. 2026-09-22 14:19 UTCGHSA enrichment
  5. 2026-09-22 13:27 UTCEG score recompute
  6. 2026-09-22 13:27 UTCGHSA enrichment
  7. 2026-09-22 11:35 UTCEG score recompute
  8. 2026-09-22 10:46 UTCEG score recompute
  9. 2026-09-22 10:45 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-90990?
CVE-2026-90990 is a medium vulnerability published on September 22, 2026. Improper neutralization of newlines in filter values in the monitoring host and service list APIs in Checkmk <2.5.0p14 allows an authenticated user to inject additional Livestatus query headers, bypassing object visibility restrictions in count queries to infer information about hosts and services…
When was CVE-2026-90990 disclosed?
CVE-2026-90990 was first published on September 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-90990 actively exploited?
CVE-2026-90990 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (34th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-90990?
CVE-2026-90990 has a CVSS base score of 5.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-90990?
No fix for CVE-2026-90990 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-90990 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-90990

Explore →

Is Your Infrastructure Affected by CVE-2026-90990?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs