🛡️ CVE-2026-47737 on Debian — puma
Description
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.
Distribution advisory
This page covers CVE-2026-47737 as tracked by Debian, for the package puma. The fix is available in version 8.0.2-1; earlier versions remain affected.
How this vulnerability can be exploited
This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity high, availability none.
Weakness class
DEBIAN-CVE-2026-47737 is classified as CWE-290: Authentication Bypass by Spoofing. Identity is inferred from something an attacker can forge, such as a header or address.
Affected software
DEBIAN-CVE-2026-47737 is recorded against 1 package.
- puma (fixed in 8.0.2-1)
Timeline and source
Published on 14 July 2026 and last revised on 4 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.
References
Details
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| puma | — | 8.0.2-1 |
References
Similar Threats
- Unknown DEBIAN-CVE-2026-47736
- High CVE-2026-47737
- High CVE-2026-47736
- Unknown DLA-3947-1
- Medium CVE-2024-45614
Site Security Check
Is puma part of your stack?
DEBIAN-CVE-2026-47737 is rated CVSS 8.0 High. BotEraser scans your installation against known CVE records and tells you whether this vulnerability applies to the versions you actually run.
Scan My Site Free →No credit card required · Results in minutes
ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.