CVE-2026-81521

MEDIUMPre-NVD 6.56.5
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

This medium-severity CVE scores 6.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2% (10th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Trending — 3 sources updated this week
6.5EG
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: 0.2%CVSS: 6.5Exploit: None knownExposed services: Not assessed

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
6.5MEDIUMmedium confidence
EG Risk
29
EG Risk 29/100

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)
Severity65% × 45%
The EG Score, 6.5 of 10.
Exploitation0.2% × 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: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
10th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

A fix is available. Apply it within your standard update timelines.

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

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

August 27, 2026

Last Modified

October 6, 2026

Advisory Details (1)

Auto-updated Aug 27, 2026
Patch available.
Web page

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(5)

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

Patch Availability(5)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatrhem/flightctl-worker-rhel9:17894880612026-09-16redhat
redhatflightctl-0:1.1.4-1.el9em2026-09-16redhat
redhatrhem/flightctl-worker-rhel9:17894868292026-09-16redhat
redhatrhem/flightctl-worker-rhel10:17894867402026-09-16redhat
redhatrhem/flightctl-worker-rhel10:17894860712026-09-16redhat

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 rangeFix by version rangeDependents
golang-mongodb-mongo-driver1.12.1+ds1-1 ... 1.8.4+ds1-3 (9 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
golang-mongodb-mongo-driver1.17.1+ds1-2, 1.17.1+ds1-3, 1.17.9+ds1-1
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
golang-mongodb-mongo-driver1.17.1+ds1-2, 1.17.1+ds1-3, 1.17.9+ds1-1
  • every version on: no fix on record
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 17× in last 7d / 77× 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.

Showing the most recent 97 of 109 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 3 repeat rows among the latest 100 are merged into the row they repeat. The 12 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  2. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  3. 2026-10-12 14:56 UTCEG score recompute
  4. 2026-10-11 19:20 UTCEG score recompute
  5. 2026-10-11 16:37 UTCEG score recompute
  6. 2026-10-11 13:55 UTCEG score recompute
  7. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  9. 2026-10-10 03:55 UTCEG score recompute
  10. 2026-10-10 03:55 UTCVendor advisory
  11. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  12. 2026-10-09 03:00 UTCEG score recompute
  13. 2026-10-09 03:00 UTCVendor advisory
  14. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  15. 2026-10-08 01:16 UTCEG score recompute
  16. 2026-10-08 01:16 UTCVendor advisory
  17. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  18. 2026-10-06 19:38 UTCEG score recompute
  19. 2026-10-06 19:38 UTCVendor advisory
  20. 2026-10-06 18:42 UTCEG score recompute
  21. 2026-10-06 18:42 UTCVendor advisory
  22. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  23. 2026-10-06 00:52 UTCEG score recompute
  24. 2026-10-06 00:52 UTCVendor advisory
  25. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 27th percentile
Show 72 more
  1. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  2. 2026-10-04 23:20 UTCVendor advisory
  3. 2026-10-03 22:38 UTCEG score recompute
  4. 2026-10-03 22:38 UTCVendor advisory
  5. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  6. 2026-10-02 21:39 UTCEG score recompute
  7. 2026-10-02 21:39 UTCVendor advisory
  8. 2026-10-02 17:57 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  9. 2026-10-01 20:57 UTCEG score recompute
  10. 2026-10-01 20:57 UTCVendor advisory
  11. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  12. 2026-09-30 20:06 UTCEG score recompute
  13. 2026-09-30 20:06 UTCVendor advisory
  14. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.4% · 26th percentile
  15. 2026-09-29 19:24 UTCEG score recompute
  16. 2026-09-29 19:24 UTCVendor advisory
  17. 2026-09-28 21:14 UTCEG score recompute
  18. 2026-09-28 21:14 UTCVendor advisory
  19. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  20. 2026-09-27 19:09 UTCEG score recompute
  21. 2026-09-27 19:09 UTCVendor advisory
  22. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  23. 2026-09-26 18:27 UTCEG score recompute
  24. 2026-09-26 18:27 UTCVendor advisory
  25. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  26. 2026-09-25 16:55 UTCVendor advisory
  27. 2026-09-24 16:13 UTCEG score recompute
  28. 2026-09-24 16:13 UTCVendor advisory
  29. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  30. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  31. 2026-09-23 15:32 UTCEG score recompute
  32. 2026-09-23 15:32 UTCVendor advisory
  33. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  34. 2026-09-22 14:49 UTCEG score recompute
  35. 2026-09-22 14:49 UTCVendor advisory
  36. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  37. 2026-09-21 14:07 UTCEG score recompute
  38. 2026-09-21 14:07 UTCVendor advisory
  39. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  40. 2026-09-20 13:25 UTCEG score recompute
  41. 2026-09-20 13:25 UTCVendor advisory
  42. 2026-09-19 12:20 UTCEG score recompute
  43. 2026-09-19 12:20 UTCVendor advisory
  44. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  45. 2026-09-18 11:39 UTCEG score recompute
  46. 2026-09-18 11:39 UTCVendor advisory
  47. 2026-09-17 10:51 UTCEG score recompute
  48. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  49. 2026-09-16 10:03 UTCEG score recompute
  50. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  51. 2026-09-15 09:21 UTCEG score recompute
  52. 2026-09-15 03:12 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  53. 2026-09-14 08:39 UTCEG score recompute
  54. 2026-09-13 07:57 UTCEG score recompute
  55. 2026-09-12 07:16 UTCEG score recompute
  56. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  57. 2026-09-11 06:34 UTCEG score recompute
  58. 2026-09-09 05:11 UTCEG score recompute
  59. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  60. 2026-09-08 04:29 UTCEG score recompute
  61. 2026-09-07 03:46 UTCEG score recompute
  62. 2026-09-06 13:48 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  63. 2026-09-06 03:04 UTCEG score recompute
  64. 2026-09-05 15:31 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  65. 2026-09-05 02:22 UTCEG score recompute
  66. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  67. 2026-09-03 00:57 UTCEG score recompute
  68. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  69. 2026-09-02 00:15 UTCEG score recompute
  70. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  71. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  72. 2026-08-30 22:46 UTCEG score recompute

Related CVEs(same product + same vendor + same CWE)

Same product

3 shown

Debian:12:golang-mongodb-mongo-driver

Frequently asked(5)

What is CVE-2026-81521?
CVE-2026-81521 is a medium-severity vulnerability; its CVE record was 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 the CVE record for CVE-2026-81521 published?
The CVE record for CVE-2026-81521 was published on August 27, 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 6, 2026; the record at its source may have been updated since.
Is CVE-2026-81521 actively exploited?
CVE-2026-81521 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (10th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-81521?
CVE-2026-81521 has a CVSS base score of 6.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-81521?
A fix for CVE-2026-81521 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-81521 are linked in the Vendor Advisories panel on this page.

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