CVE-2026-77860

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 2026-09-16. 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-2026-80286 (ENISA EUVD) · GHSA-8483-8qxh-jcf2 (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: 0.3%CVSS: 3.7Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

In NLnetLabs Unbound 1.20.0 up to and including 1.26.0, a vulnerability on the 'serve-expired' code path can cause a double decrement on the 'wait-limit' counter per client IP essentially bypassing one of the counter measures that was introduced for DNSBomb (CVE-2024-33655). A malicious actor can exploit this by controlling an authoritative zone with short TTL, so cached entries expire quickly. Each 'slow' query, one the attacker's authoritative never answers, is followed by one query for an expired cached name, which is answered immediately via the 'serve-expired' path and decrements the counter twice. This second query was named 'pump'. By alternating slow queries and pumps, the attacker keeps the per-client counter at or below the configured 'wait-limit' indefinitely, and can hold an arbitrary number of pending queries from a single source IP, up to the global mesh quota (num-queries-per-thread); eventually bypassing one of the counter measures introduced for DNSBomb (CVE-2024-33655). This vulnerability is present on the 'serve-expired' code path.

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.
Exploitation0.3% × 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: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.3%
EPSS %ILE
22nd
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
0.3% 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

September 16, 2026

Last Modified

September 23, 2026

References (1)

Vendor Advisories for CVE-2026-77860(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-1.26.1-1.hum12026-09-17redhat

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
unbound1.17.1-2 ... 1.26.1-1 (26 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 ... 1.26.0-2 (12 versions)
  • every version up to 1.26.1-1: fixed in 1.26.1-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 48× 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.

  1. 2026-11-02 16:46 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  2. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  3. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  4. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  5. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  6. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  7. 2026-10-28 01:55 UTCOSV refresh
  8. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  9. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  10. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  11. 2026-10-25 14:01 UTCEG score recompute
  12. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  13. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  14. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  15. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  16. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  17. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  18. 2026-10-18 03:11 UTCEG score recompute
  19. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  20. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  21. 2026-10-16 09:35 UTCEG score recompute
  22. 2026-10-16 09:35 UTCVendor advisory
  23. 2026-10-16 09:35 UTCGHSA enrichmentGHSA-8483-8qxh-jcf2 · GitHub severity LOW · GitHub CVSS 3.7
  24. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  25. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
Show 64 more
  1. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  2. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  3. 2026-10-12 15:37 UTCEG score recompute
  4. 2026-10-11 19:23 UTCEG score recompute
  5. 2026-10-11 16:39 UTCEG score recompute
  6. 2026-10-11 13:57 UTCEG score recompute
  7. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  9. 2026-10-10 06:49 UTCEG score recompute
  10. 2026-10-10 06:49 UTCVendor advisory
  11. 2026-10-10 06:49 UTCGHSA enrichmentGHSA-8483-8qxh-jcf2 · GitHub severity LOW · GitHub CVSS 3.7
  12. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  13. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  14. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  15. 2026-10-07 13:05 UTCEG score recompute
  16. 2026-10-07 13:05 UTCVendor advisory
  17. 2026-10-07 13:05 UTCGHSA enrichmentGHSA-8483-8qxh-jcf2 · GitHub severity LOW · GitHub CVSS 3.7
  18. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  19. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  20. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  21. 2026-10-04 19:21 UTCEG score recompute
  22. 2026-10-04 19:21 UTCVendor advisory
  23. 2026-10-04 19:21 UTCGHSA enrichmentGHSA-8483-8qxh-jcf2 · GitHub severity LOW · GitHub CVSS 3.7
  24. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  25. 2026-10-02 01:37 UTCEG score recompute
  26. 2026-10-02 01:37 UTCVendor advisory
  27. 2026-10-02 01:36 UTCGHSA enrichmentGHSA-8483-8qxh-jcf2 · GitHub severity LOW · GitHub CVSS 3.7
  28. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  29. 2026-09-29 15:24 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  30. 2026-09-29 07:52 UTCEG score recompute
  31. 2026-09-29 07:52 UTCVendor advisory
  32. 2026-09-29 07:52 UTCGHSA enrichmentGHSA-8483-8qxh-jcf2 · GitHub severity LOW · GitHub CVSS 3.7
  33. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  34. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  35. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  36. 2026-09-26 14:08 UTCEG score recompute
  37. 2026-09-26 14:08 UTCVendor advisory
  38. 2026-09-26 14:08 UTCGHSA enrichmentGHSA-8483-8qxh-jcf2 · GitHub severity LOW · GitHub CVSS 3.7
  39. 2026-09-26 00:28 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  40. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  41. 2026-09-23 20:24 UTCEG score recompute
  42. 2026-09-23 20:24 UTCVendor advisory
  43. 2026-09-23 20:24 UTCGHSA enrichmentGHSA-8483-8qxh-jcf2 · GitHub severity LOW · GitHub CVSS 3.7
  44. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  45. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  46. 2026-09-22 07:13 UTCEG score recompute
  47. 2026-09-22 07:13 UTCVendor advisory
  48. 2026-09-22 07:13 UTCGHSA enrichmentGHSA-8483-8qxh-jcf2 · GitHub severity LOW · GitHub CVSS 3.7
  49. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  50. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  51. 2026-09-19 13:29 UTCEG score recompute
  52. 2026-09-19 13:29 UTCVendor advisory
  53. 2026-09-19 13:29 UTCGHSA enrichmentGHSA-8483-8qxh-jcf2 · GitHub severity LOW · GitHub CVSS 3.7
  54. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  55. 2026-09-16 19:45 UTCGHSA enrichmentGHSA-8483-8qxh-jcf2 · GitHub severity LOW · GitHub CVSS 3.7
  56. 2026-09-16 15:25 UTCEG score recompute
  57. 2026-09-16 15:25 UTCGHSA enrichmentGHSA-8483-8qxh-jcf2 · GitHub severity LOW · GitHub CVSS 3.7
  58. 2026-09-16 14:51 UTCEG score recompute
  59. 2026-09-16 14:51 UTCGHSA enrichmentGHSA-8483-8qxh-jcf2 · GitHub severity LOW · GitHub CVSS 3.7
  60. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  61. 2026-09-16 09:31 UTCEG score recompute
  62. 2026-09-16 09:31 UTCGHSA enrichmentGHSA-8483-8qxh-jcf2 · GitHub severity LOW · GitHub CVSS 3.7
  63. 2026-09-16 08:42 UTCEG score recomputeFirst assessed: 3.7 LOW
  64. 2026-09-16 08:41 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-77860?
CVE-2026-77860 is a low-severity vulnerability; its CVE record was published on September 16, 2026. In NLnetLabs Unbound 1.20.0 up to and including 1.26.0, a vulnerability on the 'serve-expired' code path can cause a double decrement on the 'wait-limit' counter per client IP essentially bypassing one of the counter measures that was introduced for DNSBomb (CVE-2024-33655). A malicious actor can…
When was CVE-2026-77860 made public?
CVE-2026-77860 was made public on September 16, 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 September 16, 2026. EchelonGraph's copy of the record carries a last-modified date of September 23, 2026; the record at its source may have been updated since.
Is CVE-2026-77860 actively exploited?
CVE-2026-77860 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (22nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-77860?
CVE-2026-77860 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-2026-77860?
A fix for CVE-2026-77860 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-77860 are linked in the Vendor Advisories panel on this page.

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