resolv vulnerable to DoS via insufficient DNS domain name length validation (CVE-2025-24294) | HOL Guard CVE

Medium · CVSS 5.3CVE-2025-24294GHSA-XH69-987W-HRP8

resolv vulnerable to DoS via insufficient DNS domain name length validation

Answer in brief

CVE-2025-24294 records a Medium severity (CVSS 5.3) vulnerability in resolv vulnerable to DoS via insufficient DNS domain name length validation. The current sources do not mark it as known exploited. The current feed maps resolv (rubygems), resolv (rubygems), resolv (rubygems). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jul 15, 2025Updated Sep 10, 2026Source checked Sep 10, 2026First seen by HOL Aug 7, 2026Material review Sep 10, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.3
Exploitation: Not marked as known exploited
Affected software: 3 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 5.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps resolv (rubygems), resolv (rubygems), resolv (rubygems). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
resolvrubygems	>=0 <0.2.3	0.2.3
resolvrubygems	>=0.4.0 <0.6.2	0.6.2
resolvrubygems	>=0.3.0 <0.3.1	0.3.1

Recommended response

Check inventory. Check lockfiles and deployed manifests for resolv, resolv, resolv.
Review the reported fix. Update resolv to 0.2.3; resolv to 0.6.2; resolv to 0.3.1 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Jul 15, 2025
Evidence: source:osv:source_dates:source-dates:record
Source modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:record
First seen by HOL
Aug 7, 2026

Sources and claim methodology

Upstream source description

A denial of service vulnerability has been discovered in the resolv gem bundled with Ruby. ## Details The vulnerability is caused by an insufficient check on the length of a decompressed domain name within a DNS packet. An attacker can craft a malicious DNS packet containing a highly compressed domain name. When the resolv library parses such a packet, the name decompression process consumes a large amount of CPU resources, as the library does not limit the resulting length of the name. This resource consumption can cause the application thread to become unresponsive, resulting in a Denial of Service condition. ## Affected Version The vulnerability affects the resolv gem bundled with the following Ruby series: * Ruby 3.2 series: resolv version 0.2.2 and earlier * Ruby 3.3 series: resolv version 0.3.0 * Ruby 3.4 series: resolv version 0.6.1 and earlier ## Credits Thanks to Manu for discovering this issue. ## History Originally published at 2025-07-08 07:00:00 (UTC)

Quoted source text, attributed separately from HOL analysis.