CVE catalog
CVE-2020-5249
puma: CVE-2020-5249
- Severity
- Medium · CVSS 6.5
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 1.57% · Oct 25, 2026
In Puma (RubyGem) before 4.3.3 and 3.12.4, if an application using Puma allows untrusted input in an early-hints header, an attacker can use a carriage return character to end the header and inject malicious content, such as additional headers or an entirely new response body. This vulnerability is known as HTTP Response Splitting. While not an attack in itself, response splitting is a vector for several other attacks, such as cross-site scripting (XSS). This is related to CVE-2020-5247, which fixed this vulnerability but only for regular responses. This has been fixed in 4.3.3 and 3.12.4.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | puma | sid | 8.0.2-3 | fixed |
| Debian | puma | forky | 8.0.2-3 | fixed |
| Debian | puma | trixie | 6.6.0-4 | fixed |
| Debian | puma | bookworm | 5.6.5-3+deb12u1 | fixed |
| Debian | puma | bookworm-security | 5.6.5-3+deb12u2 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | puma | source | sid | 3.12.4-1 | not yet assigned | Not reported | [953122] |
| Debian | puma | source | forky | 3.12.4-1 | not yet assigned | Not reported | [953122] |
| Debian | puma | source | trixie | 3.12.4-1 | not yet assigned | Not reported | [953122] |
| Debian | puma | source | bookworm | 3.12.4-1 | not yet assigned | Not reported | [953122] |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [puma]Fixed
Details (2)
5.6.5-3+deb12u1· amd64 · bookwormFixed · Fixed:
3.12.4-1dsa · puma · debian · bookworm; dsa · puma · debian · 12
5.6.5-3+deb12u1· arm64 · bookwormFixed · Fixed:
3.12.4-1dsa · puma · debian · bookworm; dsa · puma · debian · 12
[Debian 13 (Trixie)]
- [puma]Fixed
Details (2)
6.6.0-4· amd64 · trixieFixed · Fixed:
3.12.4-1dsa · puma · debian · 13
6.6.0-4· arm64 · trixieFixed · Fixed:
3.12.4-1dsa · puma · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/suse-su-2020_3036-1.json]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2020-5249]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2020-5249]
- [https://security-tracker.debian.org/tracker/CVE-2020-5249]
[Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database] · [SUSE security advisories and VEX]