A missing lower-bound validation in the bson_new_from_buffer() function of libbson allows an integer underflow when processing BSON data with a zero-length prefix. The function reads a 32-bit document length from the input buffer but does not verify that the value is at least 5 (the minimum valid BSON document size) before using it in an array index calculation. When the length field is zero, the expression used to check the document's null terminator wraps to UINT32_MAX, causing a heap out-of-bounds read that crashes the process. An unauthorized party who can supply crafted BSON input to an application using this API can cause a denial of service.
CVE-2026-93395
MEDIUMPre-NVD 5.35.3—Trending — 4 sources updated this week
EchelonGraph scoreHIGH confidence
Score 5.3 from GitHub Security Advisory published 2026-09-17. a secondary CVSS source baseline 5.3; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.3
- EG Score
- 5.3(high)
- EG Risk
- 39(Track)EG Risk 39/100SSVC: 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 computedSeverity53% × 45%Exploitation0% × 40%Automatability100% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 15%
- KEV
- Not listed
Published
September 17, 2026
Last Modified
September 18, 2026
Advisory Details (1)
Auto-updated Sep 17, 2026No patch confirmed yet.
Vendor Advisories for CVE-2026-93395(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 11× in last 7d / 11× 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.
- 2026-09-19 17:05 UTCEG score recompute
- 2026-09-19 17:05 UTCGHSA enrichment
- 2026-09-18 19:28 UTCEPSS rescore
- 2026-09-18 19:08 UTCGHSA enrichment
- 2026-09-18 15:26 UTCEG score recompute
- 2026-09-18 15:26 UTCGHSA enrichment
- 2026-09-18 14:35 UTCEG score recompute
- 2026-09-18 14:35 UTCGHSA enrichment
- 2026-09-17 21:20 UTCEG score recompute
- 2026-09-17 20:45 UTCEG score recompute
- 2026-09-17 20:44 UTCMITRE cvelistV5first tracked
Frequently asked(5)
What is CVE-2026-93395?
CVE-2026-93395 is a medium vulnerability published on September 17, 2026. A missing lower-bound validation in the bsonnewfrombuffer() function of libbson allows an integer underflow when processing BSON data with a zero-length prefix. The function reads a 32-bit document length from the input buffer but does not verify that the value is at least 5 (the minimum valid BSON…
When was CVE-2026-93395 disclosed?
CVE-2026-93395 was first published in the National Vulnerability Database on September 17, 2026, with the most recent update on September 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-93395 actively exploited?
CVE-2026-93395 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 84.9% of all scored CVEs.
What is the CVSS score of CVE-2026-93395?
CVE-2026-93395 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-93395?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-93395, 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-2026-93395
Is Your Infrastructure Affected by CVE-2026-93395?
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