vyper default functions don't respect nonreentrancy keys

Exploitation

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

CVSS

5.3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS

• CVE-2024-32648: 0.41% estimated exploitation activity in the next 30 days; percentile 35.90 (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.

Summary Prior to v0.3.0, default() functions did not respect the @nonreentrancy decorator and the lock was not emitted. This is a known bug and was already visible in the issue tracker (https://github.com/vyperlang/vyper/issues/2455), but it is being re-issued as an advisory so that tools relying on the advisory publication list can incorporate it into their searches. A contract search was additionally performed and no vulnerable contracts were found in production. PoC after codegen: Impact No vulnerable production contracts were found. Additionally, using a lock on a default function is a very sparsely used pattern. As such, the impact is low.

Published by the source

25 Apr 2024, 19:50 UTC

Last modified by the source

10 Jun 2026, 17:14 UTC

Source last checked

26 Oct 2026, 13:30 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-m2v9-w374-5hj9

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-m2v9-w374-5hj9

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# Patch Next advisory brief: CVE-2024-32648

Advisory: vyper default functions don't respect nonreentrancy keys
IDs: CVE-2024-32648, GHSA-m2v9-w374-5hj9
Record: https://patchnext.com/advisories/cve-2024-32648 (revision 2, source checked 26 Oct 2026, 13:30 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: vyper 0.3.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI vyper: affected <= 0.2.16; fixed in 0.3.0

## Suggested inspection (read-only)
- `python -m pip show vyper`: prints the installed version. Run with the environment that serves production active.

## 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 vyper.
- 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://osv.dev/vulnerability/GHSA-m2v9-w374-5hj9 (OSV record GHSA-m2v9-w374-5hj9 lists affected ranges: PyPI vyper >=0 <0.3.0 (fixed))
- Verified: https://github.com/advisories/GHSA-m2v9-w374-5hj9 (GitHub-reviewed advisory GHSA-m2v9-w374-5hj9 lists affected ranges: PyPI vyper >=0 <=0.2.16)

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