CVE-2026-4891

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 2026-05-11. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 5.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: CISA-ADP (Vulnrichment) CVSS v3.1, EPSS, GitHub Security Advisory
Trending — 3 sources updated this week
5.3EG
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: 0.8%CVSS: 5.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

A heap-based out-of-bounds read vulnerability in the DNSSEC validation of dnsmasq allows remote attackers to cause a denial of service via a crafted DNS packet.

CVSS v3
5.3
EG Score
5.3MEDIUMmedium confidence
EG Risk
24
EG Risk 24/100

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)
Severity53% × 45%
The EG Score, 5.3 of 10.
Exploitation0.8% × 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
0.8%
EPSS %ILE
56th
KEV
Not listed

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

May 11, 2026

Last Modified

September 1, 2026

Advisory Details (6)

Auto-updated May 12, 2026
Patch available. Sources: cert.
CERT

VU#471747 - dnsmasq contains several vulnerabilities, including attacker DNS redirect, privilege escalation, and heap manipulation

https://www.kb.cert.org/vuls/id/471747
Web page

Index of /dnsmasq/CVE

https://thekelleys.org.uk/dnsmasq/CVE/
Web page

[Dnsmasq-discuss] Security - IMPORTANT

https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2026q2/018471.html
Web page

Release Pi-hole FTL v6.6.2 · pi-hole/FTL · GitHub

https://github.com/pi-hole/FTL/releases/tag/v6.6.2
Web page

[Backport release-25.11] dnsmasq: 2.92 -> 2.92rel2 by LeSuisse · Pull Request #519093 · NixOS/nixpkgs · GitHub

https://github.com/NixOS/nixpkgs/pull/519093
Web page

dnsmasq: 2.92 -> 2.92rel2 by LeSuisse · Pull Request #519082 · NixOS/nixpkgs · GitHub

https://github.com/NixOS/nixpkgs/pull/519082

Vendor Advisories for CVE-2026-4891(7)

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

Patch Availability(6)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntudnsmasq-utils (2.90-0ubuntu0.22.04.3) @ jammy2026-08-25ubuntu
redhatrhcos-4.19.9.6.202607151909-02026-07-22redhat
redhatdnsmasq-0:2.85-17.el9_6.12026-07-01redhat
redhatdnsmasq-0:2.79-36.el8_102026-05-26redhat
redhatdnsmasq-0:2.90-7.el10_22026-05-19redhat
redhatdnsmasq-0:2.85-18.el9_8.12026-05-19redhat

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

(7 across 7 ecosystems)
Alpine:v3.22(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.91-r1: fixed in 2.91-r1
—
Alpine:v3.23(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.91-r1: fixed in 2.91-r1
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.92_p2-r0: fixed in 2.92_p2-r0
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq2.85-1, 2.85-1+deb11u1
  • every version up to 2.85-1+deb11u2: fixed in 2.85-1+deb11u2
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq2.89-1, 2.90-1, 2.90-2, 2.90-3, 2.90-4~deb12u1
  • every version up to 2.90-4~deb12u2: fixed in 2.90-4~deb12u2
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq2.91-1
  • every version up to 2.91-1+deb13u1: fixed in 2.91-1+deb13u1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq2.91-1 ... 2.92~rc3-1 (9 versions)
  • every version up to 2.92-5: fixed in 2.92-5
—

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 11× in last 7d / 25× 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 100 of 251 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. None are among the latest 100 rows. The 151 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-11 19:43 UTCEG score recompute
  2. 2026-10-11 16:58 UTCEG score recompute
  3. 2026-10-11 14:22 UTCEG score recompute
  4. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  5. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  6. 2026-10-10 00:55 UTCOSV refresh
  7. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  8. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  9. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  10. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  11. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  12. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  13. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  14. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  15. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  16. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  17. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  18. 2026-09-26 00:27 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  19. 2026-09-23 17:53 UTCEPSS rescoreEPSS 6.4% · 93rd percentile
  20. 2026-09-20 20:16 UTCEPSS rescoreEPSS 6.4% · 93rd percentile
  21. 2026-09-20 09:03 UTCOSV refresh
  22. 2026-09-18 19:28 UTCEPSS rescoreEPSS 6.4% · 93rd percentile
  23. 2026-09-16 14:08 UTCEPSS rescoreEPSS 6.4% · 93rd percentile
  24. 2026-09-16 05:15 UTCEPSS rescoreEPSS 6.4% · 93rd percentile
  25. 2026-09-13 16:47 UTCEPSS rescoreEPSS 6.4% · 93rd percentile
Show 75 more
  1. 2026-09-11 14:53 UTCEPSS rescoreEPSS 6.4% · 93rd percentile
  2. 2026-09-10 09:35 UTCEPSS rescoreEPSS 6.4% · 93rd percentile
  3. 2026-09-08 22:01 UTCEPSS rescoreEPSS 6.4% · 93rd percentile
  4. 2026-09-07 16:01 UTCEPSS rescoreEPSS 6.4% · 93rd percentile
  5. 2026-09-06 13:47 UTCEPSS rescoreEPSS 6.4% · 93rd percentile
  6. 2026-09-04 05:06 UTCEPSS rescoreEPSS 6.4% · 93rd percentile
  7. 2026-09-02 14:12 UTCEPSS rescoreEPSS 6.4% · 93rd percentile
  8. 2026-09-01 13:54 UTCEPSS rescoreEPSS 6.4% · 93rd percentile
  9. 2026-09-01 12:21 UTCEG score recompute
  10. 2026-09-01 12:21 UTCVendor advisory
  11. 2026-09-01 12:21 UTCGHSA enrichmentGHSA-2qp9-xr4x-2cr9 · GitHub CVSS 5.3
  12. 2026-09-01 04:40 UTCEPSS rescoreEPSS 6.4% · 93rd percentile
  13. 2026-08-30 19:17 UTCEPSS rescoreEPSS 6.4% · 93rd percentile
  14. 2026-08-30 01:22 UTCEPSS rescoreEPSS 6.4% · 93rd percentile
  15. 2026-08-28 21:41 UTCEPSS rescoreEPSS 6.4% · 93rd percentile
  16. 2026-08-27 14:25 UTCEPSS rescoreEPSS 6.4% · 93rd percentile
  17. 2026-08-26 14:46 UTCEPSS rescoreEPSS 6.4% · 93rd percentile
  18. 2026-08-25 13:49 UTCEPSS rescoreEPSS 6.4% · 93rd percentile
  19. 2026-08-25 13:24 UTCVendor advisory
  20. 2026-08-25 13:24 UTCGHSA enrichmentGHSA-2qp9-xr4x-2cr9 · GitHub CVSS 5.3
  21. 2026-08-25 12:21 UTCEG score recompute
  22. 2026-08-25 12:21 UTCVendor advisory
  23. 2026-08-25 12:21 UTCGHSA enrichmentGHSA-2qp9-xr4x-2cr9 · GitHub CVSS 5.3
  24. 2026-08-24 13:30 UTCVendor advisory
  25. 2026-08-24 13:29 UTCGHSA enrichmentGHSA-2qp9-xr4x-2cr9 · GitHub CVSS 5.3
  26. 2026-08-24 12:26 UTCEG score recompute
  27. 2026-08-24 12:26 UTCVendor advisory
  28. 2026-08-24 12:25 UTCGHSA enrichmentGHSA-2qp9-xr4x-2cr9 · GitHub CVSS 5.3
  29. 2026-08-23 18:37 UTCEG score recompute
  30. 2026-08-23 18:37 UTCVendor advisory
  31. 2026-08-23 18:37 UTCGHSA enrichmentGHSA-2qp9-xr4x-2cr9 · GitHub CVSS 5.3
  32. 2026-08-23 00:19 UTCEPSS rescoreEPSS 6.2% · 92nd percentile
  33. 2026-08-21 23:49 UTCEPSS rescoreEPSS 6.2% · 92nd percentile
  34. 2026-08-20 22:55 UTCEPSS rescoreEPSS 6.2% · 92nd percentile
  35. 2026-08-19 17:04 UTCEPSS rescoreEPSS 6.2% · 92nd percentile
  36. 2026-08-18 13:48 UTCEPSS rescoreEPSS 6.2% · 92nd percentile
  37. 2026-08-17 11:03 UTCEG score recompute
  38. 2026-08-17 11:03 UTCVendor advisory
  39. 2026-08-17 11:03 UTCGHSA enrichmentGHSA-2qp9-xr4x-2cr9 · GitHub CVSS 5.3
  40. 2026-08-16 14:56 UTCEPSS rescoreEPSS 6.2% · 92nd percentile
  41. 2026-08-16 04:25 UTCEG score recompute
  42. 2026-08-16 04:25 UTCVendor advisory
  43. 2026-08-16 04:25 UTCGHSA enrichmentGHSA-2qp9-xr4x-2cr9 · GitHub CVSS 5.3
  44. 2026-08-16 02:14 UTCEPSS rescoreEPSS 6.2% · 92nd percentile
  45. 2026-08-15 01:30 UTCEPSS rescoreEPSS 6.2% · 92nd percentile
  46. 2026-08-14 02:57 UTCEG score recompute
  47. 2026-08-14 02:57 UTCVendor advisory
  48. 2026-08-14 02:57 UTCGHSA enrichmentGHSA-2qp9-xr4x-2cr9 · GitHub CVSS 5.3
  49. 2026-08-13 22:00 UTCEPSS rescoreEPSS 6.2% · 92nd percentile
  50. 2026-08-12 16:29 UTCEG score recompute
  51. 2026-08-12 16:29 UTCVendor advisory
  52. 2026-08-12 16:29 UTCGHSA enrichmentGHSA-2qp9-xr4x-2cr9 · GitHub CVSS 5.3
  53. 2026-08-12 13:51 UTCEPSS rescoreEPSS 6.2% · 92nd percentile
  54. 2026-08-11 02:25 UTCVendor advisory
  55. 2026-08-11 02:25 UTCGHSA enrichmentGHSA-2qp9-xr4x-2cr9 · GitHub CVSS 5.3
  56. 2026-08-10 02:20 UTCEG score recompute
  57. 2026-08-10 02:20 UTCVendor advisory
  58. 2026-08-10 02:20 UTCGHSA enrichmentGHSA-2qp9-xr4x-2cr9 · GitHub CVSS 5.3
  59. 2026-08-09 13:46 UTCEPSS rescoreEPSS 6.2% · 92nd percentile
  60. 2026-08-09 02:14 UTCEG score recompute
  61. 2026-08-09 02:14 UTCVendor advisory
  62. 2026-08-09 02:14 UTCGHSA enrichmentGHSA-2qp9-xr4x-2cr9 · GitHub CVSS 5.3
  63. 2026-08-08 16:37 UTCEPSS rescoreEPSS 6.2% · 92nd percentile
  64. 2026-08-08 01:42 UTCEG score recompute
  65. 2026-08-08 01:42 UTCVendor advisory
  66. 2026-08-08 01:42 UTCGHSA enrichmentGHSA-2qp9-xr4x-2cr9 · GitHub CVSS 5.3
  67. 2026-08-07 01:37 UTCEG score recompute
  68. 2026-08-07 01:37 UTCVendor advisory
  69. 2026-08-07 01:37 UTCGHSA enrichmentGHSA-2qp9-xr4x-2cr9 · GitHub CVSS 5.3
  70. 2026-08-06 13:47 UTCEPSS rescoreEPSS 6.2% · 92nd percentile
  71. 2026-08-05 21:57 UTCEG score recompute
  72. 2026-08-05 21:57 UTCVendor advisory
  73. 2026-08-05 21:57 UTCGHSA enrichmentGHSA-2qp9-xr4x-2cr9 · GitHub CVSS 5.3
  74. 2026-08-05 19:17 UTCEPSS rescoreEPSS 6.2% · 92nd percentile
  75. 2026-08-04 15:10 UTCEPSS rescoreEPSS 6.2% · 92nd percentile

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Frequently asked(5)

What is CVE-2026-4891?
CVE-2026-4891 is a medium-severity vulnerability; its CVE record was published on May 11, 2026. A heap-based out-of-bounds read vulnerability in the DNSSEC validation of dnsmasq allows remote attackers to cause a denial of service via a crafted DNS packet.
When was the CVE record for CVE-2026-4891 published?
The CVE record for CVE-2026-4891 was published on May 11, 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 1, 2026; the record at its source may have been updated since.
Is CVE-2026-4891 actively exploited?
CVE-2026-4891 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.8% probability of exploitation in the next 30 days (56th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-4891?
CVE-2026-4891 has a CVSS v3.1 base score of 5.3 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-4891?
A fix for CVE-2026-4891 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-4891 are linked in the Vendor Advisories panel on this page.

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