CVE-2026-80212

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-80212
StatePUBLISHED
Assignermitre
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-27 17:20:50 UTC
Updated2026-08-27 20:18:48 UTC
DescriptionAn 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.

Risk And Classification

Primary CVSS: v3.1 7.5 HIGH from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Problem Types: CWE-770 | CWE-770 CWE-770 Allocation of Resources Without Limits or Throttling

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.1CNACVSS7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Ruby Resolv affected 0.3.2 semver Not specified
CNA Ruby Resolv affected 0.4.0 0.7.2 semver Not specified

References

ReferenceSourceLinkTags
www.ruby-lang.org/en/news/2026/08/27/multiple-vulnerabilities-in-resolv [email protected] www.ruby-lang.org
github.com/ruby/resolv [email protected] github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report