CVE-2026-84970

MEDIUMNVD 5.86.2▲
EchelonGraph scoreHIGH confidence

Score 6.2 from GitHub Security Advisory published 2026-09-03. NVD baseline CVSS 5.8; sources differ by 0.4.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
6.2EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.8Exploit: None knownExposed: 0

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

A numeric truncation weakness exists in the JSON parsing component of the MongoDB C++ Driver's BSON library. An actor who controls the text that an embedding application hands to the library's public JSON parsing interface, when that text is very large, can cause the library to read memory beyond the supplied buffer and return it to the caller, to silently accept only part of the input as a complete document, or to terminate the process. No MongoDB server, credentials, or non-default configuration is required; the effect is confined to the process that uses the library.

CVSS v3
5.8
EG Score
6.2(high)
EG Risk
28(Track)
EG Risk 28/100SSVC: 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
Severity62% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
0%
KEV
Not listed

Published

September 3, 2026

Last Modified

September 10, 2026

Advisory Details (1)

Auto-updated Sep 3, 2026
No patch confirmed yet.
generic

SAML Login - MongoDB Jira - MongoDB Jira

https://jira.mongodb.org/browse/CXX-3547

Vendor Advisories for CVE-2026-84970(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
Debian:14(1)
PackageVulnerable rangeFixed inDependents
mongo-cxx-driver3.10.1-1 ... 4.5.2-1 (22 versions)——

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 18× in last 7d / 46× 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 06:36 UTCEG score recompute
  2. 2026-09-19 06:36 UTCGHSA enrichment
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-18 08:04 UTCEG score recompute
  5. 2026-09-18 08:04 UTCGHSA enrichment
  6. 2026-09-17 19:32 UTCEPSS rescore
  7. 2026-09-17 09:34 UTCEG score recompute
  8. 2026-09-17 09:34 UTCGHSA enrichment
  9. 2026-09-16 14:09 UTCEPSS rescore
  10. 2026-09-16 11:03 UTCEG score recompute
  11. 2026-09-16 11:03 UTCGHSA enrichment
  12. 2026-09-16 05:15 UTCEPSS rescore
  13. 2026-09-15 12:33 UTCGHSA enrichment
  14. 2026-09-14 14:02 UTCEG score recompute
  15. 2026-09-14 14:02 UTCGHSA enrichment
  16. 2026-09-13 15:32 UTCGHSA enrichment
  17. 2026-09-12 17:01 UTCEG score recompute
  18. 2026-09-12 17:01 UTCGHSA enrichment
  19. 2026-09-11 18:31 UTCEG score recompute
  20. 2026-09-11 18:31 UTCGHSA enrichment
  21. 2026-09-11 14:53 UTCEPSS rescore
  22. 2026-09-11 14:53 UTCEPSS rescore
  23. 2026-09-10 20:00 UTCEG score recompute
  24. 2026-09-10 20:00 UTCGHSA enrichment
  25. 2026-09-10 19:58 UTCNVD updateCVSS v3 → 5.8
Show 21 more
  1. 2026-09-10 07:48 UTCGHSA enrichment
  2. 2026-09-09 09:18 UTCEG score recompute
  3. 2026-09-09 09:18 UTCGHSA enrichment
  4. 2026-09-08 22:01 UTCEPSS rescore
  5. 2026-09-08 10:48 UTCEG score recompute
  6. 2026-09-08 10:47 UTCGHSA enrichment
  7. 2026-09-07 12:03 UTCEG score recompute
  8. 2026-09-07 12:03 UTCGHSA enrichment
  9. 2026-09-06 13:48 UTCEPSS rescore
  10. 2026-09-06 13:31 UTCEG score recompute
  11. 2026-09-06 13:31 UTCGHSA enrichment
  12. 2026-09-05 15:31 UTCEPSS rescore
  13. 2026-09-05 15:01 UTCGHSA enrichment
  14. 2026-09-04 16:31 UTCEG score recompute
  15. 2026-09-04 16:31 UTCGHSA enrichment
  16. 2026-09-03 17:59 UTCGHSA enrichment
  17. 2026-09-03 16:33 UTCEG score recompute
  18. 2026-09-03 16:33 UTCGHSA enrichment
  19. 2026-09-03 15:25 UTCEG score recompute
  20. 2026-09-03 15:04 UTCEG score recompute
  21. 2026-09-03 15:03 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-84970?
CVE-2026-84970 is a medium vulnerability published on September 3, 2026. A numeric truncation weakness exists in the JSON parsing component of the MongoDB C++ Driver's BSON library. An actor who controls the text that an embedding application hands to the library's public JSON parsing interface, when that text is very large, can cause the library to read memory beyond…
When was CVE-2026-84970 disclosed?
CVE-2026-84970 was first published in the National Vulnerability Database on September 3, 2026, with the most recent update 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-2026-84970 actively exploited?
CVE-2026-84970 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 99.5% of all scored CVEs.
What is the CVSS score of CVE-2026-84970?
CVE-2026-84970 has a CVSS v3 base score of 5.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 6.2.
How do I remediate CVE-2026-84970?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-84970, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-84970

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