CVE-2026-81529

HIGHPre-NVD 7.17.1
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 7.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3% (19th 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
7.1EG
EchelonGraph verdictPlan mitigationRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 7.1Exploit: None knownExposed services: Not assessed

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

The CVE record's CNA (MongoDB, Inc.) lists MongoDB C# Driver versions 2.0.0 up to but not including 3.11.1 as affected. No release containing a fix is confirmed on record.

Improper neutralization of delimiters in connection-URL construction allows connection-option injection in the MongoDB C# Driver. When an application passes untrusted text into the driver's connection-URL builder and round-trips the builder back into a client configuration, the untrusted text is serialized without neutralizing the URL/option delimiters and is then re-parsed as authoritative connection options. A low-privileged user of such an application can thereby introduce or suppress security-relevant connection settings.

CVSS v3
7.1
EG Score
7.1HIGHmedium confidence
EG Risk
32
EG Risk 32/100

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)
Severity71% × 45%
The EG Score, 7.1 of 10.
Exploitation0.3% × 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: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.
EPSS PROB
0.3%
EPSS %ILE
19th
KEV
Not listed

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

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.

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

September 29, 2026

Advisory Details (1)

Auto-updated Aug 27, 2026
No fix on record yet.
Web page

NuGet Gallery | MongoDB.Driver 3.11.1

https://www.nuget.org/packages/MongoDB.Driver/3.11.1

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 15× in last 7d / 57× 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.

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 89 are merged into the row they repeat.

  1. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  2. 2026-10-13 06:19 UTCEG score recompute
  3. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  4. 2026-10-12 14:56 UTCEG score recompute
  5. 2026-10-11 19:20 UTCEG score recompute
  6. 2026-10-11 16:37 UTCEG score recompute
  7. 2026-10-11 13:55 UTCEG score recompute
  8. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  9. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  10. 2026-10-10 01:46 UTCEG score recompute
  11. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  12. 2026-10-09 02:57 UTCEG score recompute
  13. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  14. 2026-10-08 01:14 UTCEG score recompute
  15. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  16. 2026-10-06 22:47 UTCEG score recompute
  17. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  18. 2026-10-06 00:52 UTCEG score recompute
  19. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  20. 2026-10-05 01:23 UTCEG score recompute
  21. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  22. 2026-10-03 16:02 UTCEG score recompute
  23. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  24. 2026-10-03 04:50 UTCEG score recompute
  25. 2026-10-02 17:57 UTCEPSS rescoreEPSS 0.3% · 19th percentile
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  1. 2026-10-01 19:52 UTCEG score recompute
  2. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  3. 2026-09-30 19:54 UTCEG score recompute
  4. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  5. 2026-09-29 19:24 UTCEG score recompute
  6. 2026-09-29 01:39 UTCEG score recompute
  7. 2026-09-28 14:42 UTCEG score recompute
  8. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  9. 2026-09-27 16:47 UTCEG score recompute
  10. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  11. 2026-09-26 18:24 UTCEG score recompute
  12. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  13. 2026-09-24 18:45 UTCEG score recompute
  14. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  15. 2026-09-23 19:53 UTCEG score recompute
  16. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  17. 2026-09-22 21:40 UTCEG score recompute
  18. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  19. 2026-09-21 23:36 UTCEG score recompute
  20. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  21. 2026-09-21 01:41 UTCEG score recompute
  22. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  23. 2026-09-19 16:47 UTCEG score recompute
  24. 2026-09-19 05:50 UTCEG score recompute
  25. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  26. 2026-09-17 20:54 UTCEG score recompute
  27. 2026-09-16 21:30 UTCEG score recompute
  28. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  29. 2026-09-16 10:29 UTCEG score recompute
  30. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  31. 2026-09-15 12:34 UTCEG score recompute
  32. 2026-09-15 03:12 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  33. 2026-09-14 03:36 UTCEG score recompute
  34. 2026-09-12 18:44 UTCEG score recompute
  35. 2026-09-11 20:48 UTCEG score recompute
  36. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  37. 2026-09-11 09:48 UTCEG score recompute
  38. 2026-09-10 11:52 UTCEG score recompute
  39. 2026-09-09 00:38 UTCEG score recompute
  40. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  41. 2026-09-07 23:02 UTCEG score recompute
  42. 2026-09-06 14:03 UTCEG score recompute
  43. 2026-09-06 13:48 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  44. 2026-09-05 16:07 UTCEG score recompute
  45. 2026-09-05 15:31 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  46. 2026-09-04 18:12 UTCEG score recompute
  47. 2026-09-04 07:08 UTCEG score recompute
  48. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  49. 2026-08-31 04:16 UTCEG score recompute
  50. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  51. 2026-08-30 06:21 UTCEG score recompute
  52. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  53. 2026-08-29 08:21 UTCEG score recompute
  54. 2026-08-28 21:42 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  55. 2026-08-28 20:41 UTCEG score recompute
  56. 2026-08-28 19:46 UTCEG score recompute
  57. 2026-08-28 00:32 UTCEG score recompute
  58. 2026-08-27 23:24 UTCEG score recompute
  59. 2026-08-27 20:26 UTCEG score recompute
  60. 2026-08-27 20:14 UTCEG score recomputeFirst assessed: 7.1 HIGH
  61. 2026-08-27 20:13 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-81529?
CVE-2026-81529 is a high-severity vulnerability; its CVE record was published on August 27, 2026. Improper neutralization of delimiters in connection-URL construction allows connection-option injection in the MongoDB C# Driver. When an application passes untrusted text into the driver's connection-URL builder and round-trips the builder back into a client configuration, the untrusted text is…
When was the CVE record for CVE-2026-81529 published?
The CVE record for CVE-2026-81529 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 September 29, 2026; the record at its source may have been updated since.
Is CVE-2026-81529 actively exploited?
CVE-2026-81529 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (19th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-81529?
CVE-2026-81529 has a CVSS base score of 7.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-81529?
No fix for CVE-2026-81529 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The CVE record's CNA (MongoDB, Inc.) lists MongoDB C# Driver versions 2.0.0 up to but not including 3.11.1 as affected. No release containing a fix is confirmed on record.

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