Date.parse in the date gem through 3.2.0 for Ruby allows ReDoS (regular expression Denial of Service) via a long string. The fixed versions are 3.2.1, 3.1.2, 3.0.2, and 2.0.1.
CVE-2021-41817
This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.5%, top 34% 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).
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 7.5
- EG Score
- 7.5(medium)
- EPSS
- 86.7%
- KEV
- Not listed
Published
January 1, 2022
Last Modified
November 21, 2024
References (10)
- cve@mitrehttps://hackerone.com/reports/1254844
- cve@mitrehttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IUXQCH6FRKANCVZO2Q7D2SQX33FP3KWN/
- cve@mitrehttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UTOJGS5IEFDK3UOO7IY4OTTFGHGLSWZF/
- cve@mitrehttps://security.gentoo.org/glsa/202401-27
- cve@mitrehttps://www.ruby-lang.org/en/news/2021/11/15/date-parsing-method-regexp-dos-cve-2021-41817/
- af854a3a-2127-422b-91ae-364da2661108https://hackerone.com/reports/1254844
- af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IUXQCH6FRKANCVZO2Q7D2SQX33FP3KWN/
- af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UTOJGS5IEFDK3UOO7IY4OTTFGHGLSWZF/
- af854a3a-2127-422b-91ae-364da2661108https://security.gentoo.org/glsa/202401-27
- af854a3a-2127-422b-91ae-364da2661108https://www.ruby-lang.org/en/news/2021/11/15/date-parsing-method-regexp-dos-cve-2021-41817/
Vendor Advisories for CVE-2021-41817(3)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2022:0708Red Hat Product SecurityHigh
Red Hat Security Advisory: rh-ruby26-ruby security, bug fix, and enhancement update
- RHSA-2022:0582Red Hat Product SecurityHigh
Red Hat Security Advisory: ruby:2.6 security update
- RHSA-2022:0581Red Hat Product SecurityHigh
Red Hat Security Advisory: ruby:2.6 security update
Patch Availability(11)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| ubuntu | ruby2.3-tcltk (2.3.1-2~ubuntu16.04.16+esm2) @ xenial | 2026-05-26 | ubuntu |
| redhat | rh-ruby27-ruby-0:2.7.6-131.el7 | 2022-10-11 | redhat |
| redhat | rh-ruby30-ruby-0:3.0.4-149.el7 | 2022-10-11 | redhat |
| redhat | ruby:2.7-8060020220728151401.ad008a3a | 2022-09-13 | redhat |
| redhat | ruby:3.0-8060020220810162001.ad008a3a | 2022-09-13 | redhat |
| redhat | ruby:2.5-8060020220715152618.ad008a3a | 2022-08-01 | redhat |
| redhat | rh-ruby26-ruby-0:2.6.9-120.el7 | 2022-02-28 | redhat |
| redhat | ruby:2.6-8010020220201152941.c27ad7f8 | 2022-02-21 | redhat |
| redhat | ruby:2.6-8020020220201131207.4cda2c84 | 2022-02-21 | redhat |
| redhat | ruby:2.6-8050020211215144356.c5368500 | 2022-02-16 | redhat |
| redhat | ruby:2.6-8040020220131135901.522a0ee4 | 2022-02-16 | redhat |
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
(1 across 1 ecosystem)
RubyGems(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| date | 0.0.1, 1.0.0, 2.0.0 | 2.0.1 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Additional Vendor Advisories
(9)
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.
- Microsoft MSRCCVE-2021-418172022-01-12
Date.parse in the date gem through 3.2.0 for Ruby allows ReDoS (regular expression Denial of Service) via a long string. The fixed versions are 3.2.1 3.1.2 3.0.2 and 2.0.1.
- Red HatRHSA-2022:0543MODERATE2021-11-15
RHSA-2022:0543 — Moderate
- Red HatRHSA-2022:0544MODERATE2021-11-15
RHSA-2022:0544 — Moderate
- Red HatRHSA-2022:5779MODERATE2021-11-15
RHSA-2022:5779 — Moderate
- Red HatRHSA-2022:6447MODERATE2021-11-15
RHSA-2022:6447 — Moderate
- Red HatRHSA-2022:6450MODERATE2021-11-15
RHSA-2022:6450 — Moderate
- Red HatRHSA-2022:6855MODERATE2021-11-15
RHSA-2022:6855 — Moderate
- Red HatRHSA-2022:6856MODERATE2021-11-15
RHSA-2022:6856 — Moderate
- UbuntuUSN-5235-1MEDIUM
Ruby vulnerabilities
Data Freshness Timeline
(refreshed 11× in last 7d / 46× 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.
- 2026-07-11 08:25 UTCEPSS rescore
- 2026-07-11 08:25 UTCEPSS rescore
- 2026-07-09 19:07 UTCEPSS rescore
- 2026-07-08 15:12 UTCEPSS rescore
- 2026-07-07 13:43 UTCEPSS rescore
- 2026-07-06 16:25 UTCEPSS rescore
- 2026-07-06 16:25 UTCEPSS rescore
- 2026-07-06 02:21 UTCEPSS rescore
- 2026-07-06 02:21 UTCEPSS rescore
- 2026-07-05 02:28 UTCEPSS rescore
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- 2026-07-04 06:29 UTCEPSS rescore
- 2026-07-04 06:29 UTCEPSS rescore
- 2026-07-02 16:57 UTCEPSS rescore
- 2026-07-01 15:04 UTCEPSS rescore
- 2026-06-30 23:20 UTCEPSS rescore
- 2026-06-30 23:20 UTCEPSS rescore
- 2026-06-30 00:04 UTCOSV refresh
- 2026-06-28 14:05 UTCEPSS rescore
- 2026-06-28 04:54 UTCEPSS rescore
- 2026-06-28 04:54 UTCEPSS rescore
- 2026-06-27 03:06 UTCEPSS rescore
- 2026-06-27 03:06 UTCEPSS rescore
- 2026-06-25 13:48 UTCEPSS rescore
- 2026-06-25 13:48 UTCEPSS rescore
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- 2026-06-24 14:03 UTCEPSS rescore
- 2026-06-24 14:03 UTCEPSS rescore
- 2026-06-22 14:24 UTCEPSS rescore
- 2026-06-21 01:58 UTCEPSS rescore
- 2026-06-21 01:58 UTCEPSS rescore
- 2026-06-19 19:24 UTCEPSS rescore
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- 2026-06-18 17:51 UTCEPSS rescore
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- 2026-06-17 17:51 UTCEPSS rescore
- 2026-06-17 17:51 UTCEPSS rescore
- 2026-06-17 17:51 UTCEPSS rescore
- 2026-06-16 17:51 UTCEPSS rescore
- 2026-06-16 17:51 UTCEPSS rescore
- 2026-06-15 17:46 UTCEPSS rescore
- 2026-06-14 23:15 UTCEPSS rescore
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- 2026-06-13 22:58 UTCEPSS rescore
- 2026-06-13 22:58 UTCEPSS rescore
- 2026-06-12 23:10 UTCEPSS rescore
- 2026-06-12 13:10 UTCOSV refresh
- 2026-06-11 13:58 UTCEPSS rescore
- 2026-06-11 13:58 UTCEPSS rescore
- 2026-06-10 22:16 UTCEPSS rescore
- 2026-06-10 22:16 UTCEPSS rescore
- 2026-06-10 13:20 UTCEPSS rescore
- 2026-06-08 14:15 UTCEPSS rescore
- 2026-06-08 14:15 UTCEPSS rescore
- 2026-06-07 15:23 UTCEPSS rescore
- 2026-06-07 15:23 UTCEPSS rescore
- 2026-06-06 13:46 UTCEPSS rescore
- 2026-06-06 13:46 UTCEPSS rescore
- 2026-06-05 22:45 UTCEPSS rescore
- 2026-06-05 06:09 UTCEPSS rescore
- 2026-06-05 06:09 UTCEPSS rescore
- 2026-06-04 13:10 UTCEPSS rescore
- 2026-06-04 13:10 UTCEPSS rescore
- 2026-06-02 20:11 UTCEPSS rescore
- 2026-06-02 20:11 UTCEPSS rescore
- 2026-06-01 13:50 UTCEPSS rescore
- 2026-06-01 13:50 UTCEPSS rescore
- 2026-05-31 22:29 UTCEPSS rescore
- 2026-05-31 22:29 UTCEPSS rescore
- 2026-05-31 00:15 UTCEPSS rescore
- 2026-05-31 00:15 UTCEPSS rescore
- 2026-05-29 13:42 UTCEPSS rescore
- 2026-05-28 13:43 UTCEPSS rescore
- 2026-05-28 13:43 UTCEPSS rescore
- 2026-05-27 13:39 UTCEPSS rescore
- 2026-05-27 13:39 UTCEPSS rescore
- 2026-05-26 13:42 UTCEPSS rescore
- 2026-05-26 13:42 UTCEPSS rescore
- 2026-05-26 07:17 UTCEPSS rescore
- 2026-05-26 07:17 UTCEPSS rescore
- 2026-05-26 07:17 UTCEPSS rescore
- 2026-05-26 05:28 UTCEG score recompute
- 2026-05-26 05:28 UTCVendor advisory
Frequently asked(5)
What is CVE-2021-41817?
When was CVE-2021-41817 disclosed?
Is CVE-2021-41817 actively exploited?
What is the CVSS score of CVE-2021-41817?
How do I remediate CVE-2021-41817?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-41817
Is Your Infrastructure Affected by CVE-2021-41817?
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