Memory Leak in Resolv Gem for Ruby Affects Memory Management

CVE-2026-80212

What is CVE-2026-80212?

A severe memory leak issue has been identified in the Resolv gem in Ruby. The vulnerability arises when the gem’s methods respond to unknown DNS resource records generated through manipulated or hijacked DNS responses. This process leads to the permanent registration of new classes for each unknown resource type or parameter encountered during the decoding of exposed DNS messages. Consequently, these classes remain in memory indefinitely, causing significant memory consumption during repeated attacks, which can degrade system performance. Systems that utilize the Resolv gem are at risk, particularly with untrusted DNS data, raising concerns around stability and resource management.

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