Reachable Assertion (CWE-617) in Elasticsearch can lead to denial of service via Input Data Manipulation (CAPEC-153). A specially crafted search request containing a null value in a specific query clause causes an internal assertion to be raised during query parsing. Because Elasticsearch treats assertion failures as fatal errors, this terminates the affected node process. A low-privileged authenticated user with read access to at least one index can exploit this condition with a single request to cause a node to terminate, disrupting search availability. In a single-node deployment this fully stops Elasticsearch; in a multi-node cluster it reduces cluster capacity for each affected node.
CVE-2026-63140
MEDIUMPre-NVD 6.56.5—Trending — 4 sources updated this week
EchelonGraph scoreHIGH confidence
Score 6.5 from GitHub Security Advisory published 2026-07-21. a secondary CVSS source baseline 6.5; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
6.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.5Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 6.5
- EG Score
- 6.5(high)
- EG Risk
- 29(Track)EG Risk 29/100SSVC: 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 computedSeverity65% × 45%Exploitation0% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS
- 14.5%
- KEV
- Not listed
Published
July 21, 2026
Last Modified
July 22, 2026
Advisory Details (1)
Auto-updated Jul 21, 2026No patch confirmed yet.
generic
Elasticsearch 8.19.19, 9.3.8, 9.4.4 Security Update (ESA-2026-64) - Security Announcements - Discuss the Elastic Stack
https://discuss.elastic.co/t/elasticsearch-8-19-19-9-3-8-9-4-4-security-update-esa-2026-64/388565Vendor Advisories for CVE-2026-63140(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 10× in last 7d / 10× 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.
- 2026-07-23 14:18 UTCEPSS rescore
- 2026-07-23 14:18 UTCEPSS rescore
- 2026-07-23 03:22 UTCEG score recompute
- 2026-07-22 22:56 UTCEG score recompute
- 2026-07-22 22:56 UTCGHSA enrichment
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 21:22 UTCEG score recompute
- 2026-07-21 21:09 UTCEG score recompute
- 2026-07-21 21:08 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Same CWE
10 shownCWE-617
Frequently asked(5)
What is CVE-2026-63140?
CVE-2026-63140 is a medium vulnerability published on July 21, 2026. Reachable Assertion (CWE-617) in Elasticsearch can lead to denial of service via Input Data Manipulation (CAPEC-153). A specially crafted search request containing a null value in a specific query clause causes an internal assertion to be raised during query parsing. Because Elasticsearch treats…
When was CVE-2026-63140 disclosed?
CVE-2026-63140 was first published in the National Vulnerability Database on July 21, 2026, with the most recent update on July 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-63140 actively exploited?
CVE-2026-63140 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 14.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-63140?
CVE-2026-63140 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-63140?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63140, 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
Explore the affected products and dependency analysis for CVE-2026-63140
Is Your Infrastructure Affected by CVE-2026-63140?
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