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% (14th 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

Also known asEUVD-2026-67205 (ENISA EUVD)Source: ENISA EUVD

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 impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity65% × 45%
Impact severity (EG Severity): CVSS 6.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
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
14th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (6.5): severity, escalated by confirmed exploitation. This CVE's 6.5 is its impact severity (EG Severity), not escalated.

EG Severity
6.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

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.

The score's inputs: 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/v2@v2.8.2

Vendor Advisories for CVE-2026-81521(7)

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

Patch Availability(6)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatrhoai/rhai-cli-rhel9:17915096892026-10-19redhat
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 8× in last 7d / 54× 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 100 of 136 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. None are among the latest 100 rows. The 36 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  2. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  3. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  4. 2026-10-30 01:55 UTCOSV refresh
  5. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  6. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  7. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  8. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  9. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  10. 2026-10-25 13:58 UTCEG score recompute
  11. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  12. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  13. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  14. 2026-10-22 13:49 UTCEG score recompute
  15. 2026-10-22 13:49 UTCVendor advisory
  16. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  17. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  18. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  19. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  20. 2026-10-18 03:09 UTCEG score recompute
  21. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  22. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  23. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  24. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  25. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.2% · 10th percentile
Show 75 more
  1. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  2. 2026-10-12 14:56 UTCEG score recompute
  3. 2026-10-11 19:20 UTCEG score recompute
  4. 2026-10-11 16:37 UTCEG score recompute
  5. 2026-10-11 13:55 UTCEG score recompute
  6. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  7. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  8. 2026-10-10 03:55 UTCEG score recompute
  9. 2026-10-10 03:55 UTCVendor advisory
  10. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  11. 2026-10-09 03:00 UTCEG score recompute
  12. 2026-10-09 03:00 UTCVendor advisory
  13. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  14. 2026-10-08 01:16 UTCEG score recompute
  15. 2026-10-08 01:16 UTCVendor advisory
  16. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  17. 2026-10-06 19:38 UTCEG score recompute
  18. 2026-10-06 19:38 UTCVendor advisory
  19. 2026-10-06 18:42 UTCEG score recompute
  20. 2026-10-06 18:42 UTCVendor advisory
  21. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  22. 2026-10-06 00:52 UTCEG score recompute
  23. 2026-10-06 00:52 UTCVendor advisory
  24. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  25. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  26. 2026-10-04 23:20 UTCVendor advisory
  27. 2026-10-03 22:38 UTCEG score recompute
  28. 2026-10-03 22:38 UTCVendor advisory
  29. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  30. 2026-10-02 21:39 UTCEG score recompute
  31. 2026-10-02 21:39 UTCVendor advisory
  32. 2026-10-02 17:57 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  33. 2026-10-01 20:57 UTCEG score recompute
  34. 2026-10-01 20:57 UTCVendor advisory
  35. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  36. 2026-09-30 20:06 UTCEG score recompute
  37. 2026-09-30 20:06 UTCVendor advisory
  38. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.4% · 26th percentile
  39. 2026-09-29 19:24 UTCEG score recompute
  40. 2026-09-29 19:24 UTCVendor advisory
  41. 2026-09-28 21:14 UTCEG score recompute
  42. 2026-09-28 21:14 UTCVendor advisory
  43. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  44. 2026-09-27 19:09 UTCEG score recompute
  45. 2026-09-27 19:09 UTCVendor advisory
  46. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  47. 2026-09-26 18:27 UTCEG score recompute
  48. 2026-09-26 18:27 UTCVendor advisory
  49. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  50. 2026-09-25 16:55 UTCVendor advisory
  51. 2026-09-24 16:13 UTCEG score recompute
  52. 2026-09-24 16:13 UTCVendor advisory
  53. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  54. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  55. 2026-09-23 15:32 UTCEG score recompute
  56. 2026-09-23 15:32 UTCVendor advisory
  57. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  58. 2026-09-22 14:49 UTCEG score recompute
  59. 2026-09-22 14:49 UTCVendor advisory
  60. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  61. 2026-09-21 14:07 UTCEG score recompute
  62. 2026-09-21 14:07 UTCVendor advisory
  63. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  64. 2026-09-20 13:25 UTCEG score recompute
  65. 2026-09-20 13:25 UTCVendor advisory
  66. 2026-09-19 12:20 UTCEG score recompute
  67. 2026-09-19 12:20 UTCVendor advisory
  68. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  69. 2026-09-18 11:39 UTCEG score recompute
  70. 2026-09-18 11:39 UTCVendor advisory
  71. 2026-09-17 10:51 UTCEG score recompute
  72. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  73. 2026-09-16 10:03 UTCEG score recompute
  74. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  75. 2026-09-15 09:21 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 (14th 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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