CVE-2026-40211

MEDIUMPre-NVD 5.35.3
EchelonGraph scoreMEDIUM confidence

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

Score 5.3 from GitHub Security Advisory published 2026-06-25. A secondary CVSS source baseline 5.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 3 sources updated this week

Also known asEUVD-2026-39350 (ENISA EUVD) · GHSA-8mqg-g8g6-fvw6 (GitHub Security Advisories)Source: ENISA EUVD

5.3EG
EchelonGraph verdictMonitorRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.7%CVSS: 5.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

An attacker can send crafted DNS over HTTP/3 queries, triggering an exception that prevents some buffer from being freed right away. The buffer will be freed at the end of the QUIC connection, but on some setups it might be possible to open enough concurrent DoH3 streams to trigger an out-of-memory condition, resulting in a denial of service.

CVSS v3
5.3
EG Score
5.3MEDIUMmedium confidence
EG Risk
39
EG Risk 39/100

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)
Severity53% × 45%
Impact severity (EG Severity): CVSS 5.3 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.7% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (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 at low or medium mission impact and sooner than that at high.
EPSS PROB
0.7%
EPSS %ILE
53rd
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 (5.3): severity, escalated by confirmed exploitation. This CVE's 5.3 is its impact severity (EG Severity), not escalated.

EG Severity
5.3 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.7% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-25). 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 low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (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)14 days if the affected system is publicly exposed; 60 days if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable yes (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

June 25, 2026

Last Modified

October 25, 2026

Advisory Details (1)

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

PowerDNS Security Advisory 2026-09 for DNSdist: Multiple issues - dnsdist documentation

https://www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-09.html

Vendor Advisories for CVE-2026-40211(1)

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

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
dnsdist1.5.1-3 ... 2.1.0-2 (44 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
dnsdist1.7.3-2 ... 2.1.2-1 (37 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
dnsdist1.9.10-1, 1.9.10-1+deb13u1, 1.9.14-0+deb13u1
  • every version up to 1.9.15-0+deb13u1: fixed in 1.9.15-0+deb13u1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
dnsdist1.9.10-1 ... 2.0.6-1 (18 versions)
  • every version up to 2.1.0-1: fixed in 2.1.0-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 39× 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 99 of 213 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. 1 repeat row among the latest 100 is merged into the row it repeats. The 114 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  2. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  3. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  4. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  5. 2026-10-25 23:37 UTCEG score recompute
  6. 2026-10-25 23:37 UTCGHSA enrichmentGHSA-8mqg-g8g6-fvw6 · GitHub CVSS 5.3
  7. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  8. 2026-10-25 14:31 UTCEG score recompute
  9. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  10. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  11. 2026-10-23 02:32 UTCEG score recompute
  12. 2026-10-23 02:32 UTCGHSA enrichmentGHSA-8mqg-g8g6-fvw6 · GitHub CVSS 5.3
  13. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  14. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  15. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  16. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  17. 2026-10-18 03:43 UTCEG score recompute
  18. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  19. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  20. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  21. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  22. 2026-10-13 22:54 UTCOSV refresh
  23. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  24. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  25. 2026-10-12 16:09 UTCEG score recompute
Show 74 more
  1. 2026-10-11 19:52 UTCEG score recompute
  2. 2026-10-11 17:05 UTCEG score recompute
  3. 2026-10-11 14:31 UTCEG score recompute
  4. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  5. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  6. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  7. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  8. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  9. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  10. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  11. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  12. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  13. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  14. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  15. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  16. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  17. 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  18. 2026-09-23 08:50 UTCEG score recompute
  19. 2026-09-23 08:50 UTCGHSA enrichmentGHSA-8mqg-g8g6-fvw6 · GitHub CVSS 5.3
  20. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  21. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  22. 2026-09-18 07:27 UTCEG score recompute
  23. 2026-09-18 07:27 UTCGHSA enrichmentGHSA-8mqg-g8g6-fvw6 · GitHub CVSS 5.3
  24. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  25. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  26. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  27. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  28. 2026-09-14 01:21 UTCEG score recompute
  29. 2026-09-14 01:21 UTCGHSA enrichmentGHSA-8mqg-g8g6-fvw6 · GitHub CVSS 5.3
  30. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  31. 2026-09-12 15:50 UTCEG score recompute
  32. 2026-09-12 15:50 UTCGHSA enrichmentGHSA-8mqg-g8g6-fvw6 · GitHub CVSS 5.3
  33. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  34. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  35. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  36. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  37. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  38. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  39. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  40. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  41. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  42. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  43. 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  44. 2026-08-30 19:35 UTCEG score recompute
  45. 2026-08-30 19:35 UTCGHSA enrichmentGHSA-8mqg-g8g6-fvw6 · GitHub CVSS 5.3
  46. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  47. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  48. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  49. 2026-08-27 23:56 UTCEG score recompute
  50. 2026-08-27 23:56 UTCGHSA enrichmentGHSA-8mqg-g8g6-fvw6 · GitHub CVSS 5.3
  51. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  52. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  53. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  54. 2026-08-24 13:11 UTCEG score recompute
  55. 2026-08-24 13:11 UTCGHSA enrichmentGHSA-8mqg-g8g6-fvw6 · GitHub CVSS 5.3
  56. 2026-08-23 11:42 UTCEG score recompute
  57. 2026-08-23 11:42 UTCGHSA enrichmentGHSA-8mqg-g8g6-fvw6 · GitHub CVSS 5.3
  58. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  59. 2026-08-22 10:38 UTCEG score recompute
  60. 2026-08-22 10:38 UTCGHSA enrichmentGHSA-8mqg-g8g6-fvw6 · GitHub CVSS 5.3
  61. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  62. 2026-08-21 08:09 UTCEG score recompute
  63. 2026-08-21 08:09 UTCGHSA enrichmentGHSA-8mqg-g8g6-fvw6 · GitHub CVSS 5.3
  64. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  65. 2026-08-20 07:05 UTCEG score recompute
  66. 2026-08-20 07:05 UTCGHSA enrichmentGHSA-8mqg-g8g6-fvw6 · GitHub CVSS 5.3
  67. 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  68. 2026-08-19 01:29 UTCEG score recompute
  69. 2026-08-19 01:29 UTCGHSA enrichmentGHSA-8mqg-g8g6-fvw6 · GitHub CVSS 5.3
  70. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  71. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  72. 2026-08-17 04:57 UTCEG score recompute
  73. 2026-08-17 04:57 UTCGHSA enrichmentGHSA-8mqg-g8g6-fvw6 · GitHub CVSS 5.3
  74. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.3% · 22nd percentile

Frequently asked(5)

What is CVE-2026-40211?
CVE-2026-40211 is a medium-severity vulnerability; its CVE record was published on June 25, 2026. An attacker can send crafted DNS over HTTP/3 queries, triggering an exception that prevents some buffer from being freed right away. The buffer will be freed at the end of the QUIC connection, but on some setups it might be possible to open enough concurrent DoH3 streams to trigger an out-of-memory…
When was CVE-2026-40211 made public?
CVE-2026-40211 was made public on June 24, 2026: that is the date its CVE record's CNA, Open-Xchange, gives for when the vulnerability was made public. The CVE record itself was published on June 25, 2026. EchelonGraph's copy of the record carries a last-modified date of October 25, 2026; the record at its source may have been updated since.
Is CVE-2026-40211 actively exploited?
CVE-2026-40211 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.7% probability of exploitation in the next 30 days (53rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-40211?
CVE-2026-40211 has a CVSS base score of 5.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-40211?
A fix for CVE-2026-40211 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-40211 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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