What is CVE-2024-11991?

CVE-2024-11991 is a medium-severity vulnerability in Dfinity Motoko, classified under Use of Uninitialized Resource. CVSS score: 5.6/10. Published 2024-12-09.

How severe is CVE-2024-11991?

Medium severity. CVSS v3 base score is 5.6 out of 10.

Vulnerability in Dfinity Motoko

CVE-2024-11991

Motoko's incremental garbage collector is impacted by an uninitialized memory access bug, caused by incorrect use of write barriers in a few locations. This vulnerability could potentially allow unauthorized read or write access to a Canister's memory. However, exploiting this bug requires the Canister to enable the incremental garbage collector or enhanced orthogonal persistence, which are non-default features in Motoko.

Published 2024-12-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.6 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.002 (14.2th percentile), scored 2026-10-04.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 14.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

Dfinity Motoko
Internet Computer Motoko — versions 0.9.0

Weakness classification (CWE)

CWE-908 — Use of Uninitialized Resource

References

6b35d637-e00f-4228-858c-b20ad6e1d07b (Patch, Issue Tracking)
6b35d637-e00f-4228-858c-b20ad6e1d07b (Vendor Advisory)

Frequently asked questions

What is CVE-2024-11991?: CVE-2024-11991 is a medium-severity vulnerability in Dfinity Motoko, classified under Use of Uninitialized Resource. CVSS score: 5.6/10. Published 2024-12-09.
How severe is CVE-2024-11991?: Medium severity. CVSS v3 base score is 5.6 out of 10.