CVE-2026-24401

MEDIUMNVD 6.56.5
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 6.5 under NVD CVSS v3. EPSS exploit probability: 0.4% (31st percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3
Trending — 3 sources updated this week

Also known asEUVD-2026-4603 (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: 0.4%CVSS: 6.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. In versions 0.9rc2 and below, avahi-daemon can be crashed via a segmentation fault by sending an unsolicited mDNS response containing a recursive CNAME record, where the alias and canonical name point to the same domain (e.g., "h.local" as a CNAME for "h.local"). This causes unbounded recursion in the lookup_handle_cname function, leading to stack exhaustion. The vulnerability affects record browsers where AVAHI_LOOKUP_USE_MULTICAST is set explicitly, which includes record browsers created by resolvers used by nss-mdns. This issue is patched in commit 78eab31128479f06e30beb8c1cbf99dd921e2524, which is part of version 0.9-rc3.

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.
Exploitation0.3% × 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
0.4%
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 (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.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS. 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: 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.

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

January 24, 2026

Last Modified

October 23, 2026

Advisory Details (3)

Auto-updated Aug 6, 2026
Patch available. Sources: github_commit, github.
GitHub advisoryMentions a patch (unverified)

Uncontrolled recursion in lookup_handle_cname (CVE-2026-24401) · Advisory · avahi/avahi · GitHub

https://github.com/avahi/avahi/security/advisories/GHSA-h4vp-5m8j-f6w3
Web page

Uncontrolled recursion in `lookup_handle_cname` caused by recursive CNAMEs · Issue #501 · avahi/avahi · GitHub

https://github.com/avahi/avahi/issues/501
GitHub commit

commit 78eab3112847 (avahi/avahi)

Fix landed in avahi/avahi commit 78eab3112847 — awaiting tagged release

https://github.com/avahi/avahi/commit/78eab31128479f06e30beb8c1cbf99dd921e2524

Vendor Advisories for CVE-2026-24401(1)

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

Patch Availability(2)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntupython3-avahi (0.8-18ubuntu1.1) @ resolute2026-10-23ubuntu
redhatavahi-main-0.9~rc4-0.1.hum12026-04-28redhat

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

(5 across 5 ecosystems)
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
avahi—
  • every version up to 0.8-r25: fixed in 0.8-r25
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
avahi0.8-10 ... 0.8-9 (17 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
avahi0.8-10 ... 0.8-18 (10 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
avahi0.8-16, 0.8-17, 0.8-18
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
avahi0.8-16, 0.8-17
  • every version up to 0.8-18: fixed in 0.8-18
—

Weakness Classification(1)

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

Additional Vendor Advisories

(1)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 9× 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 214 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 115 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

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

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Frequently asked(5)

What is CVE-2026-24401?
CVE-2026-24401 is a medium-severity vulnerability; its CVE record was published on January 24, 2026. Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. In versions 0.9rc2 and below, avahi-daemon can be crashed via a segmentation fault by sending an unsolicited mDNS response containing a recursive CNAME record, where the alias and canonical…
When was the CVE record for CVE-2026-24401 published?
The CVE record for CVE-2026-24401 was published on January 24, 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 23, 2026; the record at its source may have been updated since.
Is CVE-2026-24401 actively exploited?
CVE-2026-24401 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-2026-24401?
CVE-2026-24401 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-24401?
A fix for CVE-2026-24401 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-24401 are linked in the Vendor Advisories panel on this page.

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