CVE-2026-84971

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreHIGH confidence

Score 6.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-03. a secondary CVSS source baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: None knownExposed: 0

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

Improper handling of an unexpected value size in the decryption path of a client-side encryption library can cause a failed internal check that terminates the process using the library. A party able to place a suitably formed encrypted value where an application will decrypt it, or able to control the responses the application receives, may cause that application to stop running.

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 computed
Severity65% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
5%
KEV
Not listed

Published

September 3, 2026

Last Modified

September 17, 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/MONGOCRYPT-971

Vendor Advisories for CVE-2026-84971(1)

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

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFixed inDependents
libmongocrypt1.10.0-1 ... 1.9.1-1 (23 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
libmongocrypt1.13.2-1 ... 1.20.4-1 (13 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
libmongocrypt1.13.2-1 ... 1.20.4-1 (13 versions)——

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 20× in last 7d / 49× 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 09:56 UTCEG score recompute
  2. 2026-09-19 09:56 UTCGHSA enrichment
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-18 11:56 UTCEG score recompute
  5. 2026-09-18 11:56 UTCGHSA enrichment
  6. 2026-09-17 19:32 UTCEPSS rescore
  7. 2026-09-17 14:01 UTCGHSA enrichment
  8. 2026-09-17 10:55 UTCEG score recompute
  9. 2026-09-17 10:55 UTCGHSA enrichment
  10. 2026-09-16 14:09 UTCEPSS rescore
  11. 2026-09-16 13:00 UTCEG score recompute
  12. 2026-09-16 13:00 UTCGHSA enrichment
  13. 2026-09-16 05:15 UTCEPSS rescore
  14. 2026-09-15 15:05 UTCEG score recompute
  15. 2026-09-15 15:05 UTCGHSA enrichment
  16. 2026-09-15 03:12 UTCEPSS rescore
  17. 2026-09-15 03:12 UTCEPSS rescore
  18. 2026-09-14 17:03 UTCGHSA enrichment
  19. 2026-09-13 19:09 UTCEG score recompute
  20. 2026-09-13 19:09 UTCGHSA enrichment
  21. 2026-09-12 21:14 UTCEG score recompute
  22. 2026-09-12 21:14 UTCGHSA enrichment
  23. 2026-09-11 23:19 UTCEG score recompute
  24. 2026-09-11 23:19 UTCGHSA enrichment
  25. 2026-09-11 14:53 UTCEPSS rescore
Show 24 more
  1. 2026-09-11 14:53 UTCEPSS rescore
  2. 2026-09-11 01:24 UTCEG score recompute
  3. 2026-09-11 01:24 UTCGHSA enrichment
  4. 2026-09-10 03:29 UTCGHSA enrichment
  5. 2026-09-09 05:34 UTCEG score recompute
  6. 2026-09-09 05:34 UTCGHSA enrichment
  7. 2026-09-08 22:01 UTCEPSS rescore
  8. 2026-09-08 07:39 UTCEG score recompute
  9. 2026-09-08 07:39 UTCGHSA enrichment
  10. 2026-09-07 09:44 UTCEG score recompute
  11. 2026-09-07 09:43 UTCGHSA enrichment
  12. 2026-09-06 13:48 UTCEPSS rescore
  13. 2026-09-06 11:44 UTCEG score recompute
  14. 2026-09-06 11:44 UTCGHSA enrichment
  15. 2026-09-05 15:31 UTCEPSS rescore
  16. 2026-09-05 13:49 UTCGHSA enrichment
  17. 2026-09-04 15:54 UTCEG score recompute
  18. 2026-09-04 15:54 UTCGHSA enrichment
  19. 2026-09-03 17:58 UTCGHSA enrichment
  20. 2026-09-03 16:33 UTCEG score recompute
  21. 2026-09-03 16:33 UTCGHSA enrichment
  22. 2026-09-03 15:25 UTCEG score recompute
  23. 2026-09-03 15:04 UTCEG score recompute
  24. 2026-09-03 15:03 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-84971?
CVE-2026-84971 is a medium vulnerability published on September 3, 2026. Improper handling of an unexpected value size in the decryption path of a client-side encryption library can cause a failed internal check that terminates the process using the library. A party able to place a suitably formed encrypted value where an application will decrypt it, or able to control…
When was CVE-2026-84971 disclosed?
CVE-2026-84971 was first published in the National Vulnerability Database on September 3, 2026, with the most recent update on September 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-84971 actively exploited?
CVE-2026-84971 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 94.7% of all scored CVEs.
What is the CVSS score of CVE-2026-84971?
CVE-2026-84971 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-84971?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-84971, 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-2026-84971

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