idna accepts Punycode labels that do not produce any non-ASCII when decoded

Exploitation

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

CVSS 4.0

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

EPSS

• CVE-2024-12224: 0.23% estimated exploitation activity in the next 30 days; percentile 13.93 (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.

idna 0.5.0 and earlier accepts Punycode labels that do not produce any non-ASCII output, which means that either ASCII labels or the empty root label can be masked such that they appear unequal without IDNA processing or when processed with a different implementation and equal when processed with idna 0.5.0 or earlier. Concretely, example.org and xn--example-.org become equal after processing by idna 0.5.0 or earlier. Also, example.org.xn-- and example.org. become equal after processing by idna 0.5.0 or earlier. In applications using idna (but not in idna itself) this may be able to lead to privilege escalation when host name comparison is part of a privilege check and the behavior is combined with a client that resolves domains with such labels instead of treating them as errors that preclude DNS resolution / URL fetching and with the attacker managing to introduce a DNS entry (and TLS certificate) for an xn---masked name that turns into the name of the target when processed by idna…

Published by the source

9 Dec 2024, 20:41 UTC

Last modified by the source

30 May 2025, 15:01 UTC

Source last checked

26 Oct 2026, 15:38 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-h97m-ww89-6jmq

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# Patch Next advisory brief: CVE-2024-12224

Advisory: `idna` accepts Punycode labels that do not produce any non-ASCII when decoded
IDs: CVE-2024-12224, GHSA-h97m-ww89-6jmq
Record: https://patchnext.com/advisories/cve-2024-12224 (revision 1, source checked 26 Oct 2026, 15:38 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: idna 1.0.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io idna: affected < 1.0.0; fixed in 1.0.0

## Suggested inspection (read-only)
- crates.io idna: 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 idna.
- 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-h97m-ww89-6jmq (GitHub-reviewed advisory GHSA-h97m-ww89-6jmq lists affected ranges: crates.io idna >=0 <1.0.0)

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