CVE-2021-41819

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 2.9%, top 14% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 3%CVSS: 7.5Exploit: None knownExposed: 0

A fix is available — apply it.

CGI::Cookie.parse in Ruby through 2.6.8 mishandles security prefixes in cookie names. This also affects the CGI gem through 0.3.0 for Ruby.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
35(Track)
EG Risk 35/100SSVC: Track

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
Severity75% × 45%
Exploitation3% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
3%
EPSS %ILE
86%
KEV
Not listed

Published

January 1, 2022

Last Modified

May 22, 2025

References (12)

Vendor Advisories for CVE-2021-41819(8)

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

Patch Availability(14)

Vendor / EcosystemFixed in / PatchReleasedSource
ubunturuby2.7-doc (2.7.0-5ubuntu1.6) @ focal2026-05-26ubuntu
redhatruby4-0-main-4.0.0-33.3.hum12026-04-17redhat
redhatruby3-3-main-3.3.10-23.1.hum12026-04-09redhat
redhatruby3-4-main-3.4.8-31.1.hum12026-04-09redhat
redhatrh-ruby30-ruby-0:3.0.4-149.el72022-10-11redhat
redhatrh-ruby27-ruby-0:2.7.6-131.el72022-10-11redhat
redhatruby:3.0-8060020220810162001.ad008a3a2022-09-13redhat
redhatruby:2.7-8060020220728151401.ad008a3a2022-09-13redhat
redhatruby:2.5-8060020220715152618.ad008a3a2022-08-01redhat
redhatrh-ruby26-ruby-0:2.6.9-120.el72022-02-28redhat
redhatruby:2.6-8020020220201131207.4cda2c842022-02-21redhat
redhatruby:2.6-8010020220201152941.c27ad7f82022-02-21redhat
redhatruby:2.6-8040020220131135901.522a0ee42022-02-16redhat
redhatruby:2.6-8050020211215144356.c53685002022-02-16redhat

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

(17 across 17 ecosystems)
Alpine:v3.12(1)
PackageVulnerable rangeFixed inDependents
ruby—2.7.5-r0—
Alpine:v3.13(1)
PackageVulnerable rangeFixed inDependents
ruby—2.7.5-r0—
Alpine:v3.14(1)
PackageVulnerable rangeFixed inDependents
ruby—2.7.5-r0—
Alpine:v3.15(1)
PackageVulnerable rangeFixed inDependents
ruby—3.0.3-r0—
Alpine:v3.16(1)
PackageVulnerable rangeFixed inDependents
ruby—3.0.3-r0—
Alpine:v3.17(1)
PackageVulnerable rangeFixed inDependents
ruby—3.0.3-r0—
Alpine:v3.18(1)
PackageVulnerable rangeFixed inDependents
ruby—3.0.3-r0—
Alpine:v3.19(1)
PackageVulnerable rangeFixed inDependents
ruby—3.0.3-r0—
Alpine:v3.20(1)
PackageVulnerable rangeFixed inDependents
ruby—3.0.3-r0—
Alpine:v3.21(1)
PackageVulnerable rangeFixed inDependents
ruby—3.0.3-r0—
Alpine:v3.22(1)
PackageVulnerable rangeFixed inDependents
ruby—3.0.3-r0—
Alpine:v3.23(1)
PackageVulnerable rangeFixed inDependents
ruby—3.0.3-r0—
Alpine:v3.24(1)
PackageVulnerable rangeFixed inDependents
ruby—3.0.3-r0—
Debian:10(1)
PackageVulnerable rangeFixed inDependents
ruby2.52.5.5-3, 2.5.5-3+deb10u1, 2.5.5-3+deb10u2, 2.5.5-3+deb10u32.5.5-3+deb10u4—
Debian:11(1)
PackageVulnerable rangeFixed inDependents
ruby2.72.7.4-12.7.4-1+deb11u1—
Debian:9(1)
PackageVulnerable rangeFixed inDependents
ruby2.32.3.3-1 ... 2.3.3-1+deb9u9 (11 versions)2.3.3-1+deb9u11—
RubyGems(1)
PackageVulnerable rangeFixed inDependents
cgi0.1.00.1.0.1—

Weakness Classification(1)

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

Additional Vendor Advisories

(7)

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 8× 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 134 total refreshes for this CVE.

  1. 2026-08-25 13:46 UTCEPSS rescore
  2. 2026-08-24 14:13 UTCEPSS rescore
  3. 2026-08-23 00:16 UTCEPSS rescore
  4. 2026-08-21 23:46 UTCEPSS rescore
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  7. 2026-08-19 17:01 UTCEPSS rescore
  8. 2026-08-19 11:59 UTCOSV refresh
  9. 2026-08-18 13:45 UTCEPSS rescore
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  11. 2026-08-16 14:53 UTCEPSS rescore
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  22. 2026-08-04 10:34 UTCEPSS rescore
  23. 2026-08-04 07:27 UTCOSV refresh
  24. 2026-08-03 10:33 UTCEPSS rescore
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  1. 2026-08-01 04:13 UTCEPSS rescore
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  5. 2026-07-26 14:52 UTCEPSS rescore
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  7. 2026-07-25 14:15 UTCEPSS rescore
  8. 2026-07-24 14:15 UTCEPSS rescore
  9. 2026-07-23 14:16 UTCEPSS rescore
  10. 2026-07-23 02:04 UTCEG score recompute
  11. 2026-07-22 22:51 UTCEG score recompute
  12. 2026-07-22 14:06 UTCEPSS rescore
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  18. 2026-07-18 10:02 UTCEPSS rescore
  19. 2026-07-18 10:02 UTCEPSS rescore
  20. 2026-07-18 04:29 UTCOSV refresh
  21. 2026-07-16 17:00 UTCEPSS rescore
  22. 2026-07-16 17:00 UTCEPSS rescore
  23. 2026-07-15 16:55 UTCEPSS rescore
  24. 2026-07-15 16:55 UTCEPSS rescore
  25. 2026-07-15 01:58 UTCEPSS rescore
  26. 2026-07-13 22:27 UTCEPSS rescore
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  30. 2026-07-12 05:44 UTCEPSS rescore
  31. 2026-07-11 08:25 UTCEPSS rescore
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  33. 2026-07-09 19:07 UTCEPSS rescore
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  35. 2026-07-07 13:43 UTCEPSS rescore
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  42. 2026-07-04 06:29 UTCEPSS rescore
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  44. 2026-07-02 16:57 UTCEPSS rescore
  45. 2026-07-01 15:04 UTCEPSS rescore
  46. 2026-06-30 23:20 UTCEPSS rescore
  47. 2026-06-30 23:20 UTCEPSS rescore
  48. 2026-06-30 00:18 UTCOSV refresh
  49. 2026-06-29 14:04 UTCEPSS rescore
  50. 2026-06-28 14:05 UTCEPSS rescore
  51. 2026-06-28 04:54 UTCEPSS rescore
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  55. 2026-06-25 13:48 UTCEPSS rescore
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  57. 2026-06-24 14:03 UTCEPSS rescore
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  60. 2026-06-19 19:24 UTCEPSS rescore
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  62. 2026-06-18 17:51 UTCEPSS rescore
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  70. 2026-06-13 22:58 UTCEPSS rescore
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  72. 2026-06-12 23:10 UTCEPSS rescore
  73. 2026-06-12 13:10 UTCOSV refresh
  74. 2026-06-11 13:58 UTCEPSS rescore
  75. 2026-06-11 13:58 UTCEPSS rescore

Frequently asked(5)

What is CVE-2021-41819?
CVE-2021-41819 is a high vulnerability published on January 1, 2022. CGI::Cookie.parse in Ruby through 2.6.8 mishandles security prefixes in cookie names. This also affects the CGI gem through 0.3.0 for Ruby.
When was CVE-2021-41819 disclosed?
CVE-2021-41819 was first published in the National Vulnerability Database on January 1, 2022, with the most recent update on May 22, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-41819 actively exploited?
CVE-2021-41819 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 3% probability of exploitation in the next 30 days, which ranks it in the top 14.0% of all scored CVEs.
What is the CVSS score of CVE-2021-41819?
CVE-2021-41819 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2021-41819?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-41819, 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.

Dependency Blast Radius

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