CVE-2020-25682

HIGHNVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

Score 8.1 from GitHub Security Advisory (severity: HIGH) published 2022-05-24. NVD baseline CVSS 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this weekElevated
8.1
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 71%
CISA-KEV: Not listedEPSS: 71%CVSS: 8.1Exploit: NoneExposed: 0

A fix is available — apply it.

A flaw was found in dnsmasq before 2.83. A buffer overflow vulnerability was discovered in the way dnsmasq extract names from DNS packets before validating them with DNSSEC data. An attacker on the network, who can create valid DNS replies, could use this flaw to cause an overflow with arbitrary data in a heap-allocated memory, possibly executing code on the machine. The flaw is in the rfc1035.c:extract_name() function, which writes data to the memory pointed by name assuming MAXDNAME*2 bytes are available in the buffer. However, in some code execution paths, it is possible extract_name() gets passed an offset from the base buffer, thus reducing, in practice, the number of available bytes that can be written in the buffer. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

CVSS v3
8.1
EG Score
8.1(medium)
EG Risk
—
EPSS
99.3%
KEV
Not listed

Published

January 20, 2021

Last Modified

November 4, 2025

References (15)

Patch Availability(4)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntudnsmasq-utils (2.80-1.1ubuntu1.2) @ focal2026-05-26ubuntu
redhatdnsmasq-0:2.79-13.el8_3.12021-01-19redhat
redhatdnsmasq-0:2.79-6.el8_1.12021-01-19redhat
redhatdnsmasq-0:2.79-11.el8_2.22021-01-19redhat

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.

Weakness Classification(2)

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

All Vendor Advisories

(5)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 10× in last 7d / 30× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

  1. 2026-07-22 22:37 UTCEG score recompute
  2. 2026-07-22 14:05 UTCEPSS rescore
  3. 2026-07-21 15:22 UTCEPSS rescore
  4. 2026-07-21 15:22 UTCEPSS rescore
  5. 2026-07-20 17:04 UTCEPSS rescore
  6. 2026-07-20 17:04 UTCEPSS rescore
  7. 2026-07-19 03:22 UTCOSV refresh
  8. 2026-07-19 02:26 UTCEPSS rescore
  9. 2026-07-19 02:26 UTCEPSS rescore
  10. 2026-07-16 16:59 UTCEPSS rescore
  11. 2026-07-15 16:55 UTCEPSS rescore
  12. 2026-07-15 01:57 UTCEPSS rescore
  13. 2026-07-12 05:44 UTCEPSS rescore
  14. 2026-07-11 08:25 UTCEPSS rescore
  15. 2026-07-11 08:25 UTCEPSS rescore
  16. 2026-07-09 19:07 UTCEPSS rescore
  17. 2026-07-07 13:43 UTCEPSS rescore
  18. 2026-07-07 13:43 UTCEPSS rescore
  19. 2026-07-04 06:29 UTCEPSS rescore
  20. 2026-07-04 06:28 UTCEPSS rescore
  21. 2026-07-01 15:03 UTCEPSS rescore
  22. 2026-07-01 09:48 UTCOSV refresh
  23. 2026-06-28 14:05 UTCEPSS rescore
  24. 2026-06-28 04:54 UTCEPSS rescore
  25. 2026-06-28 04:54 UTCEPSS rescore
Show 47 more
  1. 2026-06-25 13:47 UTCEPSS rescore
  2. 2026-06-24 14:03 UTCEPSS rescore
  3. 2026-06-24 14:03 UTCEPSS rescore
  4. 2026-06-23 21:31 UTCEPSS rescore
  5. 2026-06-23 21:31 UTCEPSS rescore
  6. 2026-06-21 01:57 UTCEPSS rescore
  7. 2026-06-21 01:57 UTCEPSS rescore
  8. 2026-06-19 19:23 UTCEPSS rescore
  9. 2026-06-18 17:50 UTCEPSS rescore
  10. 2026-06-17 17:50 UTCEPSS rescore
  11. 2026-06-15 17:46 UTCEPSS rescore
  12. 2026-06-14 23:15 UTCEPSS rescore
  13. 2026-06-13 22:58 UTCEPSS rescore
  14. 2026-06-13 22:58 UTCEPSS rescore
  15. 2026-06-13 15:43 UTCOSV refresh
  16. 2026-06-12 23:10 UTCEPSS rescore
  17. 2026-06-11 13:58 UTCEPSS rescore
  18. 2026-06-10 22:16 UTCEPSS rescore
  19. 2026-06-10 22:16 UTCEPSS rescore
  20. 2026-06-10 13:20 UTCEPSS rescore
  21. 2026-06-07 15:23 UTCEPSS rescore
  22. 2026-06-07 15:23 UTCEPSS rescore
  23. 2026-06-06 13:45 UTCEPSS rescore
  24. 2026-06-06 13:45 UTCEPSS rescore
  25. 2026-06-05 22:45 UTCEPSS rescore
  26. 2026-06-05 22:45 UTCEPSS rescore
  27. 2026-06-05 06:08 UTCEPSS rescore
  28. 2026-06-05 06:08 UTCEPSS rescore
  29. 2026-06-04 13:10 UTCEPSS rescore
  30. 2026-06-04 13:10 UTCEPSS rescore
  31. 2026-06-02 20:11 UTCEPSS rescore
  32. 2026-06-02 20:11 UTCEPSS rescore
  33. 2026-05-31 22:29 UTCEPSS rescore
  34. 2026-05-31 22:29 UTCEPSS rescore
  35. 2026-05-31 00:15 UTCEPSS rescore
  36. 2026-05-31 00:15 UTCEPSS rescore
  37. 2026-05-29 13:42 UTCEPSS rescore
  38. 2026-05-28 13:43 UTCEPSS rescore
  39. 2026-05-28 13:43 UTCEPSS rescore
  40. 2026-05-27 13:39 UTCEPSS rescore
  41. 2026-05-26 21:50 UTCEG score recompute
  42. 2026-05-26 21:50 UTCVendor advisory
  43. 2026-05-26 21:50 UTCGHSA enrichment
  44. 2026-05-26 13:42 UTCEPSS rescore
  45. 2026-05-26 13:42 UTCEPSS rescore
  46. 2026-05-26 07:17 UTCEPSS rescore
  47. 2026-05-26 07:17 UTCEPSS rescore

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Frequently asked(5)

What is CVE-2020-25682?
CVE-2020-25682 is a high vulnerability published on January 20, 2021. A flaw was found in dnsmasq before 2.83. A buffer overflow vulnerability was discovered in the way dnsmasq extract names from DNS packets before validating them with DNSSEC data. An attacker on the network, who can create valid DNS replies, could use this flaw to cause an overflow with arbitrary…
When was CVE-2020-25682 disclosed?
CVE-2020-25682 was first published in the National Vulnerability Database on January 20, 2021, with the most recent update on November 4, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2020-25682 actively exploited?
CVE-2020-25682 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 99.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2020-25682?
CVE-2020-25682 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2020-25682?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2020-25682, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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