resolv vulnerable to DoS via insufficient DNS domain name length validation

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.6 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U · score source

EPSS

• CVE-2025-24294: 0.66% estimated exploitation activity in the next 30 days; percentile 51.44 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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)

Published by the source

15 Jul 2025, 14:37 UTC

Last modified by the source

15 Jul 2025, 22:56 UTC

Source last checked

26 Oct 2026, 15:51 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-xh69-987w-hrp8

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# Patch Next advisory brief: CVE-2025-24294

Advisory: resolv vulnerable to DoS via insufficient DNS domain name length validation
IDs: CVE-2025-24294, GHSA-xh69-987w-hrp8
Record: https://patchnext.com/advisories/cve-2025-24294 (revision 1, source checked 26 Oct 2026, 15:51 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.6)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: resolv 0.6.2, 0.3.1, 0.2.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- RubyGems resolv: affected < 0.2.3; >= 0.4.0, < 0.6.2; >= 0.3.0, < 0.3.1; fixed in 0.2.3, 0.3.1, 0.6.2

## Suggested inspection (read-only)
- RubyGems resolv: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on resolv.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-xh69-987w-hrp8 (GitHub-reviewed advisory GHSA-xh69-987w-hrp8 lists affected ranges: RubyGems resolv >=0 =0.4.0 =0.3.0 <0.3.1)

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