DEBIAN-CVE-2026-80212
- Source
- https://security-tracker.debian.org/tracker/CVE-2026-80212
- Import Source
- https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-80212.json
- JSON Data
- https://api.osv.dev/v1/vulns/DEBIAN-CVE-2026-80212
- Upstream
- Published
- 2026-08-27T17:20:50Z
- Modified
- 2026-11-07T19:00:43Z
- Severity
-
- 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
- Summary
- [none]
- Details
-
An issue was discovered in the resolv gem before 0.7.2 for Ruby. Resolv::DNS::Resource.get_class, Resolv::DNS::Resource::Generic.create, and Resolv::DNS::SvcParam::Generic.create generate a new class for each unknown DNS resource record (type, class) pair, or each unknown SvcParamKey, encountered while decoding a response. Each generated class was permanently registered both as a constant on Resource (or SvcParam::Generic) and as an entry in a class-lookup hash (ClassHash), and thus the class remained reachable through that constant after the response was discarded. Type and class are each 16-bit values, and thus an attacker controlling DNS responses (a spoofed response, or a malicious or hijacked upstream DNS server) has roughly 2^32 distinct (type, class) pairs to choose from. A single response of a few hundred kilobytes carrying tens of thousands of distinct unknown types permanently grows process memory by tens of megabytes; repeated responses accumulate without bound and are never reclaimed by garbage collection, because the constant keeps each class alive. Any code path that calls Resolv::DNS::Message.decode on attacker-influenced DNS responses is affected. resolv is a default gem, and thus this is reachable from a plain Ruby installation without any additional dependency.
- References
Affected packages
Debian:12 / ruby3.1
Package
- Name
- ruby3.1
- Purl
- pkg:deb/debian/ruby3.1?arch=source&distro=bookworm
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0 Unknown introduced version / All previous versions are affected
Debian:13 / ruby3.3
Package
- Name
- ruby3.3
- Purl
- pkg:deb/debian/ruby3.3?arch=source&distro=trixie
Debian:14 / ruby3.3
Package
- Name
- ruby3.3
- Purl
- pkg:deb/debian/ruby3.3?arch=source&distro=forky