Ruby through 2.4.7, 2.5.x through 2.5.6, and 2.6.x through 2.6.4 allows HTTP Response Splitting. If a program using WEBrick inserts untrusted input into the response header, an attacker can exploit it to insert a newline character to split a header, and inject malicious content to deceive clients. NOTE: this issue exists because of an incomplete fix for CVE-2017-17742, which addressed the CRLF vector, but did not address an isolated CR or an isolated LF.
CVE-2019-16254
Score 5.3 from GitHub Security Advisory published 2022-05-24. NVD baseline CVSS 5.3; sources differ by 0.0.
- Lower severity and no public exploit yet
A fix is available — apply it.
- CVSS v3
- 5.3
- EG Score
- 5.3(medium)
- EG Risk
- 30(Track)EG Risk 30/100SSVC: 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 computedSeverity53% × 45%Exploitation5% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 5%
- EPSS %ILE
- 91%
- KEV
- Not listed
Published
November 26, 2019
Last Modified
November 21, 2024
References (32)
- cve@mitrehttp://lists.opensuse.org/opensuse-security-announce/2020-03/msg00041.html
- cve@mitrehttps://hackerone.com/reports/331984
- cve@mitrehttps://lists.debian.org/debian-lts-announce/2019/11/msg00025.html
- cve@mitrehttps://lists.debian.org/debian-lts-announce/2019/12/msg00009.html
- cve@mitrehttps://lists.debian.org/debian-lts-announce/2020/08/msg00027.html
- cve@mitrehttps://lists.debian.org/debian-lts-announce/2023/04/msg00033.html
- cve@mitrehttps://seclists.org/bugtraq/2019/Dec/31
- cve@mitrehttps://seclists.org/bugtraq/2019/Dec/32
- cve@mitrehttps://security.gentoo.org/glsa/202003-06
- cve@mitrehttps://www.debian.org/security/2019/dsa-4586
- cve@mitrehttps://www.debian.org/security/2019/dsa-4587
- cve@mitrehttps://www.oracle.com/security-alerts/cpujan2020.html
- cve@mitrehttps://www.ruby-lang.org/ja/news/2019/10/01/http-response-splitting-in-webrick-cve-2019-16254/
- cve@mitrehttps://www.ruby-lang.org/ja/news/2019/10/01/ruby-2-4-8-released/
- cve@mitrehttps://www.ruby-lang.org/ja/news/2019/10/01/ruby-2-5-7-released/
Vendor Advisories for CVE-2019-16254(9)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2026:8838Red Hat Product SecurityMedium
Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update
- RHSA-2026:7307Red Hat Product SecurityMedium
Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update
- RHSA-2026:7305Red Hat Product SecurityMedium
Red Hat Security Advisory: Red Hat Hardened Images RPMs 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
- RHSA-2021:2587Red Hat Product SecurityMedium
Red Hat Security Advisory: ruby:2.5 security, bug fix, and enhancement update
- RHSA-2021:2588Red Hat Product SecurityMedium
Red Hat Security Advisory: ruby:2.6 security, bug fix, and enhancement update
- RHSA-2021:2230Red Hat Product SecurityMedium
Red Hat Security Advisory: rh-ruby26-ruby security, bug fix, and enhancement update
- +1 more
Patch Availability(10)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| ubuntu | ruby2.3-tcltk (2.3.1-2~ubuntu16.04.14) @ xenial | 2026-05-27 | ubuntu |
| redhat | ruby4-0-main-4.0.0-33.3.hum1 | 2026-04-17 | redhat |
| redhat | ruby3-4-main-3.4.8-31.1.hum1 | 2026-04-09 | redhat |
| redhat | ruby3-3-main-3.3.10-23.1.hum1 | 2026-04-09 | redhat |
| redhat | ruby:2.6-8010020220201152941.c27ad7f8 | 2022-02-21 | redhat |
| redhat | ruby:2.6-8020020220201131207.4cda2c84 | 2022-02-21 | redhat |
| redhat | ruby:2.5-8040020200923213910.522a0ee4 | 2021-06-29 | redhat |
| redhat | ruby:2.6-8040020210430142949.522a0ee4 | 2021-06-29 | redhat |
| redhat | rh-ruby26-ruby-0:2.6.7-119.el7 | 2021-06-03 | redhat |
| redhat | rh-ruby25-ruby-0:2.5.9-9.el7 | 2021-05-26 | 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.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Additional Vendor Advisories
(2)
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-2019-162542020-09-25
Ruby through 2.4.7 2.5.x through 2.5.6 and 2.6.x through 2.6.4 allows HTTP Response Splitting. If a program using WEBrick inserts untrusted input into the response header an attacker can exploit it to insert a newline character to split a header and inject malicious content to deceive clients. NOTE: this issue exists because of an incomplete fix for CVE-2017-17742 which addressed the CRLF vector but did not address an isolated CR or an isolated LF.
- UbuntuUSN-4201-1MEDIUM
Ruby vulnerabilities
Data Freshness Timeline
(refreshed 9× in last 7d / 43× 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.
- 2026-07-25 14:14 UTCEPSS rescore
- 2026-07-24 14:14 UTCEPSS rescore
- 2026-07-24 14:14 UTCEPSS rescore
- 2026-07-23 14:15 UTCEPSS rescore
- 2026-07-23 01:41 UTCEG score recompute
- 2026-07-22 22:21 UTCEG score recompute
- 2026-07-22 14:05 UTCEPSS rescore
- 2026-07-21 15:22 UTCEPSS rescore
- 2026-07-21 15:22 UTCEPSS rescore
- 2026-07-20 17:04 UTCEPSS rescore
- 2026-07-20 17:04 UTCEPSS rescore
- 2026-07-20 00:48 UTCOSV refresh
- 2026-07-19 14:28 UTCEPSS rescore
- 2026-07-19 14:28 UTCEPSS rescore
- 2026-07-19 02:26 UTCEPSS rescore
- 2026-07-19 02:26 UTCEPSS rescore
- 2026-07-18 10:01 UTCEPSS rescore
- 2026-07-16 16:59 UTCEPSS rescore
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- 2026-07-15 16:55 UTCEPSS rescore
- 2026-07-15 16:55 UTCEPSS rescore
- 2026-07-13 22:27 UTCEPSS rescore
- 2026-07-13 06:10 UTCEPSS rescore
- 2026-07-13 06:10 UTCEPSS rescore
- 2026-07-12 05:43 UTCEPSS rescore
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- 2026-07-12 05:43 UTCEPSS rescore
- 2026-07-11 08:24 UTCEPSS rescore
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- 2026-07-09 19:06 UTCEPSS rescore
- 2026-07-08 15:11 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 02:20 UTCEPSS rescore
- 2026-07-05 02:27 UTCEPSS rescore
- 2026-07-04 06:28 UTCEPSS rescore
- 2026-07-02 15:52 UTCOSV refresh
- 2026-07-01 15:03 UTCEPSS rescore
- 2026-07-01 15:03 UTCEPSS rescore
- 2026-06-30 23:20 UTCEPSS rescore
- 2026-06-28 14:04 UTCEPSS rescore
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- 2026-06-27 03:06 UTCEPSS rescore
- 2026-06-25 13:47 UTCEPSS rescore
- 2026-06-25 13:47 UTCEPSS rescore
- 2026-06-24 14:03 UTCEPSS rescore
- 2026-06-24 14:03 UTCEPSS rescore
- 2026-06-23 21:31 UTCEPSS rescore
- 2026-06-23 21:30 UTCEPSS rescore
- 2026-06-22 14:23 UTCEPSS rescore
- 2026-06-22 14:23 UTCEPSS rescore
- 2026-06-21 14:54 UTCEPSS rescore
- 2026-06-21 14:54 UTCEPSS rescore
- 2026-06-21 01:57 UTCEPSS rescore
- 2026-06-21 01:57 UTCEPSS rescore
- 2026-06-19 19:23 UTCEPSS rescore
- 2026-06-19 19:23 UTCEPSS rescore
- 2026-06-18 17:50 UTCEPSS rescore
- 2026-06-17 17:50 UTCEPSS rescore
- 2026-06-16 17:50 UTCEPSS rescore
- 2026-06-15 17:45 UTCEPSS rescore
- 2026-06-14 23:15 UTCEPSS rescore
- 2026-06-14 23:15 UTCEPSS rescore
- 2026-06-14 13:43 UTCOSV refresh
- 2026-06-13 22:58 UTCEPSS rescore
- 2026-06-12 23:09 UTCEPSS rescore
- 2026-06-11 13:58 UTCEPSS rescore
- 2026-06-11 13:58 UTCEPSS rescore
- 2026-06-10 22:16 UTCEPSS rescore
- 2026-06-10 13:19 UTCEPSS rescore
- 2026-06-08 14:15 UTCEPSS rescore
- 2026-06-08 14:14 UTCEPSS rescore
- 2026-06-07 15:23 UTCEPSS rescore
- 2026-06-07 15:22 UTCEPSS rescore
- 2026-06-06 13:45 UTCEPSS rescore
- 2026-06-06 13:45 UTCEPSS rescore
- 2026-06-05 22:45 UTCEPSS rescore
- 2026-06-05 22:45 UTCEPSS rescore
- 2026-06-05 06:08 UTCEPSS rescore
- 2026-06-05 06:08 UTCEPSS rescore
- 2026-06-04 13:10 UTCEPSS rescore
- 2026-06-04 13:10 UTCEPSS rescore
- 2026-06-02 20:11 UTCEPSS rescore
- 2026-06-01 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 00:14 UTCEPSS rescore
- 2026-05-31 00:14 UTCEPSS rescore
- 2026-05-29 13:42 UTCEPSS rescore
- 2026-05-28 13:43 UTCEPSS rescore
- 2026-05-27 13:38 UTCEPSS rescore
- 2026-05-27 11:05 UTCEG score recompute
- 2026-05-27 11:05 UTCVendor advisory
- 2026-05-27 11:05 UTCGHSA enrichment
- 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
Frequently asked(5)
What is CVE-2019-16254?
When was CVE-2019-16254 disclosed?
Is CVE-2019-16254 actively exploited?
What is the CVSS score of CVE-2019-16254?
How do I remediate CVE-2019-16254?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2019-16254
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