CVE catalog
CVE-2026-47737
Puma is a Ruby/Rack web server built for parallelism. From 5.5.0 until 7.2.1 and 8.0.2, Puma is vulnerable to source IP spoofing when set_remote_address proxy_protocol: :v1 is enabled and persistent c
- Severity
- High · CVSS 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.18% · Oct 25, 2026
Puma is a Ruby/Rack web server built for parallelism. From 5.5.0 until 7.2.1 and 8.0.2, Puma is vulnerable to source IP spoofing when set_remote_address proxy_protocol: :v1 is enabled and persistent connections are used because Puma incorrectly re-parses PROXY protocol headers after each keep-alive request on the same connection, allowing an attacker to inject a second PROXY header and overwrite REMOTE_ADDR. This issue is fixed in versions 7.2.1 and 8.0.2.
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 | vulnerable |
| Debian | puma | bookworm | 5.6.5-3+deb12u1 | vulnerable |
| Debian | puma | bookworm-security | 5.6.5-3+deb12u2 | fixed |
| Cpe | puma | Not reported | Not reported | vulnerable |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | puma | source | sid | 8.0.2-1 | not yet assigned | Not reported | Not reported |
| Debian | puma | source | forky | 8.0.2-1 | not yet assigned | Not reported | Not reported |
| Debian | puma | source | trixie | (unfixed) | not yet assigned | Not reported | Not reported |
| Debian | puma | source | bookworm | 5.6.5-3+deb12u2 | not yet assigned | Not reported | Not reported |
Notes
[trixie] puma: Minor issue
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [puma]Affected
Details (2)
5.6.5-3+deb12u1· amd64 · bookwormAffected · Fixed:
5.6.5-3+deb12u2nvd · puma · debian · bookworm; nvd · puma · debian · 12
5.6.5-3+deb12u1· arm64 · bookwormAffected · Fixed:
5.6.5-3+deb12u2nvd · puma · debian · bookworm; nvd · puma · debian · 12
[Debian 13 (Trixie)]
- [puma]Affected
Details (2)
6.6.0-4· amd64 · trixieAffected
nvd · puma · debian · 13
6.6.0-4· arm64 · trixieAffected
nvd · puma · debian · 13
Observed:
References
- [https://nvd.nist.gov/vuln/detail/CVE-2026-47737]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-47737]
- [https://security-tracker.debian.org/tracker/CVE-2026-47737]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-47737.json]
[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]