CVE-2026-80212Network attack vectorHinoki check available

Service interruption via retained DNS record classes

Published Aug 27, 2026 · Updated Aug 27, 2026

Memory exhaustion in Ruby Resolv 0.3.1 and earlier and 0.4.0 through 0.7.1 allows remote attackers to stop services via DNS responses. Resource.get_class and Generic.create create and permanently register a class for every unknown record type, class pair, or SvcParamKey. Exploitation requires a Resolv decoding path to receive attacker-controlled DNS responses; repeated replies retain memory until the process stops.

CVSS severity7.5
High
EPSS probability0.57%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Memory exhaustion in Ruby Resolv 0.3.1 and earlier and 0.4.0 through 0.7.1 allows remote attackers to stop services via DNS responses. Resource.get_class and Generic.create create and permanently register a class for every unknown record type, class pair, or SvcParamKey. Exploitation requires a Resolv decoding path to receive attacker-controlled DNS responses; repeated replies retain memory until the process stops.

The record

CVE
CVE-2026-80212
Published
Aug 27, 2026
Updated
Aug 27, 2026
Vendor
libwww-perl
Product
Resolv
Classifications
CWE-770, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <0.3.2
  2. Affected versionversion=0.4.0 <0.7.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

libwww-perl · Resolvversion=0 <0.3.2; version=0.4.0 <0.7.2

Published CVSS scores

7.5MITRECVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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