An off-by-one error in the BSON bulk document writer in the MongoDB C Driver can write one zero byte immediately past a heap allocation when a document ends at a specific buffer boundary. An actor who can influence the size of documents serialized by an embedding application can corrupt adjacent process memory or terminate the process. Reaching this issue requires the application to use the BSON bulk-writer API and produce a precise cumulative document size.
CVE-2026-106431
MEDIUMPre-NVD 5.75.7—Trending — 3 sources updated this week
EchelonGraph scoreMEDIUM confidence
This medium-severity CVE scores 5.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: <0.1% (below the 1st 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
5.7EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: <0.1%CVSS: 5.7Exploit: None knownExposed services: Not assessed
No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.
- CVSS v3
- 5.7
- EG Score
- 5.7MEDIUMmedium confidence
- EG Risk
- 26EG Risk 26/100
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 (value × EchelonGraph’s weight)Severity57% × 45%The EG Score, 5.7 of 10.Exploitation0% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.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
- <0.1%
- EPSS %ILE
- below the 1st
- KEV
- Not listed
SSVC (CISA's decision table, applied by EchelonGraph)Track 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). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
Published
October 8, 2026
Last Modified
October 8, 2026
Advisory Details (1)
Auto-updated Oct 8, 2026No fix on record yet.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 9× in last 7d / 9× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
- 2026-10-10 20:26 UTCEG score recompute
- 2026-10-10 19:59 UTCEPSS rescoreEPSS <0.1% · below the 1st percentile
- 2026-10-09 20:40 UTCEG score recompute
- 2026-10-09 20:06 UTCEPSS rescoreEPSS <0.1% · below the 1st percentile
- 2026-10-08 20:20 UTCEG score recompute
- 2026-10-08 19:25 UTCEG score recompute
- 2026-10-08 19:18 UTCEG score recompute
- 2026-10-08 18:55 UTCEG score recompute
- 2026-10-08 18:54 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-106431?
CVE-2026-106431 is a medium vulnerability published on October 8, 2026. An off-by-one error in the BSON bulk document writer in the MongoDB C Driver can write one zero byte immediately past a heap allocation when a document ends at a specific buffer boundary. An actor who can influence the size of documents serialized by an embedding application can corrupt adjacent…
When was the CVE record for CVE-2026-106431 published?
The CVE record for CVE-2026-106431 was published on October 8, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 8, 2026; the record at its source may have been updated since.
Is CVE-2026-106431 actively exploited?
CVE-2026-106431 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a <0.1% probability of exploitation in the next 30 days (below the 1st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-106431?
CVE-2026-106431 has a CVSS base score of 5.7 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-106431?
No fix for CVE-2026-106431 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.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-106431
Is Your Infrastructure Affected by CVE-2026-106431?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.