CVE-2026-81521

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 89% of all CVEs by exploit prediction. 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
Trending — Patch released 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

A fix is available — apply it.

The MongoDB Go Driver's client-level bulk write operation may accept a caller-supplied database name containing a reserved separator character without escaping it before the name is used to build the target namespace for the operation. An application that passes untrusted input as a database name could therefore have the write directed at a database and collection other than the ones it intended. Only the Client.BulkWrite API is affected.

CVSS v3
6.5
EG Score
6.5(medium)
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
11%
KEV
Not listed

Published

August 27, 2026

Last Modified

August 28, 2026

Advisory Details (1)

Auto-updated Aug 27, 2026
No patch confirmed yet.
generic

mongo-driver module - go.mongodb.org/mongo-driver/v2 - Go Packages

https://pkg.go.dev/go.mongodb.org/mongo-driver/[email protected]

Vendor Advisories for CVE-2026-81521(1)

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

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatflightctl-0:1.1.4-1.el9em2026-09-16redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFixed inDependents
golang-mongodb-mongo-driver1.12.1+ds1-1 ... 1.8.4+ds1-3 (9 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
golang-mongodb-mongo-driver1.17.1+ds1-2, 1.17.1+ds1-3, 1.17.9+ds1-1——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
golang-mongodb-mongo-driver1.17.1+ds1-2, 1.17.1+ds1-3, 1.17.9+ds1-1——

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 44× 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. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 11:39 UTCEG score recompute
  3. 2026-09-18 11:39 UTCVendor advisory
  4. 2026-09-17 10:51 UTCEG score recompute
  5. 2026-09-16 14:08 UTCEPSS rescore
  6. 2026-09-16 10:03 UTCEG score recompute
  7. 2026-09-16 05:15 UTCEPSS rescore
  8. 2026-09-15 09:21 UTCEG score recompute
  9. 2026-09-15 03:12 UTCEPSS rescore
  10. 2026-09-15 03:12 UTCEPSS rescore
  11. 2026-09-14 08:39 UTCEG score recompute
  12. 2026-09-13 07:57 UTCEG score recompute
  13. 2026-09-12 07:16 UTCEG score recompute
  14. 2026-09-11 14:53 UTCEPSS rescore
  15. 2026-09-11 14:53 UTCEPSS rescore
  16. 2026-09-11 06:34 UTCEG score recompute
  17. 2026-09-09 05:11 UTCEG score recompute
  18. 2026-09-08 22:01 UTCEPSS rescore
  19. 2026-09-08 04:29 UTCEG score recompute
  20. 2026-09-07 03:46 UTCEG score recompute
  21. 2026-09-06 13:48 UTCEPSS rescore
  22. 2026-09-06 03:04 UTCEG score recompute
  23. 2026-09-05 15:31 UTCEPSS rescore
  24. 2026-09-05 02:22 UTCEG score recompute
  25. 2026-09-04 05:07 UTCEPSS rescore
Show 19 more
  1. 2026-09-03 00:57 UTCEG score recompute
  2. 2026-09-02 14:12 UTCEPSS rescore
  3. 2026-09-02 00:15 UTCEG score recompute
  4. 2026-09-01 13:54 UTCEPSS rescore
  5. 2026-09-01 04:40 UTCEPSS rescore
  6. 2026-09-01 04:40 UTCEPSS rescore
  7. 2026-08-30 22:46 UTCEG score recompute
  8. 2026-08-30 19:18 UTCEPSS rescore
  9. 2026-08-30 19:17 UTCEPSS rescore
  10. 2026-08-30 01:22 UTCEPSS rescore
  11. 2026-08-29 22:04 UTCEG score recompute
  12. 2026-08-28 21:42 UTCEPSS rescore
  13. 2026-08-28 20:42 UTCEG score recompute
  14. 2026-08-28 19:46 UTCEG score recompute
  15. 2026-08-28 00:32 UTCEG score recompute
  16. 2026-08-27 23:25 UTCEG score recompute
  17. 2026-08-27 20:26 UTCEG score recompute
  18. 2026-08-27 20:15 UTCEG score recompute
  19. 2026-08-27 20:13 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-81521?
CVE-2026-81521 is a medium vulnerability published on August 27, 2026. The MongoDB Go Driver's client-level bulk write operation may accept a caller-supplied database name containing a reserved separator character without escaping it before the name is used to build the target namespace for the operation. An application that passes untrusted input as a database name…
When was CVE-2026-81521 disclosed?
CVE-2026-81521 was first published in the National Vulnerability Database on August 27, 2026, with the most recent update on August 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-81521 actively exploited?
CVE-2026-81521 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 89.4% of all scored CVEs.
What is the CVSS score of CVE-2026-81521?
CVE-2026-81521 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-81521?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-81521, 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

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