CVE-2020-25686

LOWNVD 3.73.7—
EchelonGraph scoreMEDIUM confidence

Score 3.7 from GitHub Security Advisory published 2022-05-24. NVD baseline CVSS 3.7; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Elevated
3.7EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 4.9%CVSS: 3.7Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

A flaw was found in dnsmasq before version 2.83. When receiving a query, dnsmasq does not check for an existing pending request for the same name and forwards a new request. By default, a maximum of 150 pending queries can be sent to upstream servers, so there can be at most 150 queries for the same name. This flaw allows an off-path attacker on the network to substantially reduce the number of attempts that it would have to perform to forge a reply and have it accepted by dnsmasq. This issue is mentioned in the "Birthday Attacks" section of RFC5452. If chained with CVE-2020-25684, the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity.

CVSS v3
3.7
EG Score
3.7LOWmedium confidence
EG Risk
37
EG Risk 37/100CISA SSVC

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
Severity37% × 45%
Exploitation40% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track* or Attend at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
4.9%
EPSS %ILE
91st
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* or Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (EG-KEV: elevated) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

January 20, 2021

Last Modified

November 4, 2025

References (15)

Vendor Advisories for CVE-2020-25686(1)

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

Patch Availability(11)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatredhat-virtualization-host-0:4.3.13-20210127.0.el7_92021-02-03redhat
redhatredhat-virtualization-host-0:4.4.4-20210201.0.el8_32021-02-03redhat
redhatdnsmasq-0:2.66-14.el7_2.32021-01-25redhat
redhatdnsmasq-0:2.66-21.el7_3.32021-01-25redhat
redhatdnsmasq-0:2.79-6.el8_1.12021-01-19redhat
redhatdnsmasq-0:2.76-16.el7_9.12021-01-19redhat
redhatdnsmasq-0:2.76-2.el7_4.32021-01-19redhat
redhatdnsmasq-0:2.79-13.el8_3.12021-01-19redhat
redhatdnsmasq-0:2.76-7.el7_6.22021-01-19redhat
redhatdnsmasq-0:2.76-10.el7_7.22021-01-19redhat
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.

Affected Packages

(20 across 20 ecosystems)
Alpine:v3.10(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.11(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.12(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.13(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.14(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.15(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.16(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.17(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.18(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.19(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.20(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.21(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.22(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.23(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Debian:10(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq2.80-1
  • every version up to 2.80-1+deb10u1: fixed in 2.80-1+deb10u1
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-1: fixed in 2.83-1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-1: fixed in 2.83-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-1: fixed in 2.83-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-1: fixed in 2.83-1
—

Weakness Classification(2)

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

Additional Vendor Advisories

(11)

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 7× in last 7d / 29× 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.

Showing the most recent 100 of 173 total refreshes for this CVE.

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

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCknqyf263/dnspooq
    First seen Jan 23, 2021

    DNSpooq - dnsmasq cache poisoning (CVE-2020-25686, CVE-2020-25684, CVE-2020-25685)

    Open source ↗

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

Frequently asked(5)

What is CVE-2020-25686?
CVE-2020-25686 is a low vulnerability published on January 20, 2021. A flaw was found in dnsmasq before version 2.83. When receiving a query, dnsmasq does not check for an existing pending request for the same name and forwards a new request. By default, a maximum of 150 pending queries can be sent to upstream servers, so there can be at most 150 queries for the…
When was CVE-2020-25686 disclosed?
CVE-2020-25686 was first published 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-2020-25686 actively exploited?
CVE-2020-25686 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 4.9% probability of exploitation in the next 30 days (91st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2020-25686?
CVE-2020-25686 has a CVSS v3 base score of 3.7 (NVD).
How do I remediate CVE-2020-25686?
A fix for CVE-2020-25686 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2020-25686 are linked in the Vendor Advisories panel on this page.

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