CVE-2026-41637

LOWPre-NVD 3.73.7
EchelonGraph scoreMEDIUM confidence

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

Score 3.7 from GitHub Security Advisory (severity: LOW) published 2026-07-22. A secondary CVSS source baseline 3.7; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source

Also known asEUVD-2026-47665 (ENISA EUVD) · GHSA-6cj4-j994-m7pr (GitHub Security Advisories)Source: ENISA EUVD

3.7EG
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: 0.4%CVSS: 3.7Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

In NLnet Labs Unbound 1.22.0 up to and including 1.25.1, client terminated DNS-over-QUIC (DoQ) queries are not accounted properly by Unbound resulting in low-cost inflation of the waiting number of replies for already in-flight resolution queries. This results in degradation of resolution service for new clients for already in-flight queries. A malicious actor can exploit the vulnerability by issuing DoQ queries for query names that need resolution and proceeding on immediately terminating the query by one of STOP_SENDING/RESET_STREAM/CONNECTION_CLOSE QUIC frames. Those terminated DoQ queries are not properly counted for and keep inflating the number of waiting replies for in-flight queries. When the maximum is reached, it results in silent query drops for new clients needing resolution for already in-flight queries. This vulnerability needs Unbound to be compiled with DoQ support ('--with-libngtcp2') and the 'quic-port' to be configured for the listening interfaces. Additionally, a malicious actor needs access to multiple source IPs to bypass the by-default configured 'wait-limit' option.

CVSS v3
3.7
EG Score
3.7LOWmedium confidence
EG Risk
17
EG Risk 17/100

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)
Severity37% × 45%
Impact severity (EG Severity): CVSS 3.7 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.4% × 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
0.4%
EPSS %ILE
31st
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 (3.7): severity, escalated by confirmed exploitation. This CVE's 3.7 is its impact severity (EG Severity), not escalated.

EG Severity
3.7 LOWCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.4% 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

July 22, 2026

Last Modified

October 24, 2026

References (1)

Vendor Advisories for CVE-2026-41637(3)

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 / EcosystemFix (by version range) / PatchReleasedSource
redhatunbound-main-1.25.2-0.1.hum12026-07-22redhat

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

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
unbound1.13.1-1 ... 1.25.2-1 (47 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
unbound1.17.1-2 ... 1.26.2-1 (27 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
unbound1.22.0-2 ... 1.26.0-2 (15 versions)
  • every version up to 1.26.1-0+deb13u1: fixed in 1.26.1-0+deb13u1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
unbound1.22.0-2 ... 1.25.1-1 (9 versions)
  • every version up to 1.25.2-1: fixed in 1.25.2-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 31× 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 its CVE.org record (CNA or CISA ADP). 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). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 179 rows 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 79 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 16:52 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  2. 2026-11-12 16:33 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  3. 2026-11-11 16:39 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  4. 2026-11-10 16:44 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  5. 2026-11-09 16:35 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  6. 2026-11-08 16:39 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  7. 2026-11-07 16:39 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  8. 2026-11-06 16:37 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  9. 2026-11-04 16:35 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  10. 2026-11-03 16:48 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  11. 2026-11-02 16:44 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  12. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  13. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  14. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  15. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  16. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  17. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  18. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  19. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  20. 2026-10-25 14:29 UTCEchelonGraph re-scored
  21. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  22. 2026-10-24 13:35 UTCEchelonGraph re-scored
  23. 2026-10-24 13:35 UTCVendor advisory
  24. 2026-10-24 13:35 UTCGHSA enrichmentGHSA-6cj4-j994-m7pr · GitHub severity LOW · GitHub CVSS 3.7
  25. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.4% · 29th percentile
Show 75 more
  1. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  2. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  3. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  4. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  5. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  6. 2026-10-18 03:41 UTCEchelonGraph re-scored
  7. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  8. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  9. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  10. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  11. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  12. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  13. 2026-10-12 16:08 UTCEchelonGraph re-scored
  14. 2026-10-11 19:50 UTCEchelonGraph re-scored
  15. 2026-10-11 17:04 UTCEchelonGraph re-scored
  16. 2026-10-11 14:30 UTCEchelonGraph re-scored
  17. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  18. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  19. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  20. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  21. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  22. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  23. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  24. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  25. 2026-10-04 15:00 UTCEchelonGraph re-scored
  26. 2026-10-04 15:00 UTCVendor advisory
  27. 2026-10-04 15:00 UTCGHSA enrichmentGHSA-6cj4-j994-m7pr · GitHub severity LOW · GitHub CVSS 3.7
  28. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  29. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  30. 2026-10-01 10:17 UTCEchelonGraph re-scored
  31. 2026-10-01 10:17 UTCVendor advisory
  32. 2026-10-01 10:17 UTCGHSA enrichmentGHSA-6cj4-j994-m7pr · GitHub severity LOW · GitHub CVSS 3.7
  33. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  34. 2026-09-28 05:19 UTCEchelonGraph re-scored
  35. 2026-09-28 05:19 UTCVendor advisory
  36. 2026-09-28 05:19 UTCGHSA enrichmentGHSA-6cj4-j994-m7pr · GitHub severity LOW · GitHub CVSS 3.7
  37. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  38. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  39. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  40. 2026-09-22 23:59 UTCEchelonGraph re-scored
  41. 2026-09-22 23:59 UTCVendor advisory
  42. 2026-09-22 23:59 UTCGHSA enrichmentGHSA-6cj4-j994-m7pr · GitHub severity LOW · GitHub CVSS 3.7
  43. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  44. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  45. 2026-09-18 03:11 UTCEchelonGraph re-scored
  46. 2026-09-18 03:11 UTCVendor advisory
  47. 2026-09-18 03:11 UTCGHSA enrichmentGHSA-6cj4-j994-m7pr · GitHub severity LOW · GitHub CVSS 3.7
  48. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  49. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  50. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  51. 2026-09-14 08:02 UTCEchelonGraph re-scored
  52. 2026-09-14 08:02 UTCVendor advisory
  53. 2026-09-14 08:02 UTCGHSA enrichmentGHSA-6cj4-j994-m7pr · GitHub severity LOW · GitHub CVSS 3.7
  54. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  55. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  56. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  57. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  58. 2026-09-11 03:18 UTCEchelonGraph re-scored
  59. 2026-09-11 03:18 UTCVendor advisory
  60. 2026-09-11 03:18 UTCGHSA enrichmentGHSA-6cj4-j994-m7pr · GitHub severity LOW · GitHub CVSS 3.7
  61. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  62. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  63. 2026-09-07 21:42 UTCEchelonGraph re-scored
  64. 2026-09-07 21:42 UTCVendor advisory
  65. 2026-09-07 21:42 UTCGHSA enrichmentGHSA-6cj4-j994-m7pr · GitHub severity LOW · GitHub CVSS 3.7
  66. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  67. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  68. 2026-09-04 13:56 UTCEchelonGraph re-scored
  69. 2026-09-04 13:56 UTCVendor advisory
  70. 2026-09-04 13:56 UTCGHSA enrichmentGHSA-6cj4-j994-m7pr · GitHub severity LOW · GitHub CVSS 3.7
  71. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  72. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  73. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  74. 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  75. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.3% · 18th percentile

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

Frequently asked(5)

What is CVE-2026-41637?
CVE-2026-41637 is a low-severity vulnerability; its CVE record was published on July 22, 2026. In NLnet Labs Unbound 1.22.0 up to and including 1.25.1, client terminated DNS-over-QUIC (DoQ) queries are not accounted properly by Unbound resulting in low-cost inflation of the waiting number of replies for already in-flight resolution queries. This results in degradation of resolution service…
When was CVE-2026-41637 made public?
CVE-2026-41637 was made public on July 22, 2026: that is the date its CVE record's CNA, NLnet Labs, gives for when the vulnerability was made public. The CVE record itself was published on July 22, 2026. EchelonGraph's copy of the record carries a last-modified date of October 24, 2026; the record at its source may have been updated since.
Is CVE-2026-41637 actively exploited?
CVE-2026-41637 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (31st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-41637?
CVE-2026-41637 has a CVSS base score of 3.7 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-41637?
A fix for CVE-2026-41637 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-41637 are linked in the Vendor Advisories panel on this page.

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