CVE-2024-11991 | Uninitialized memory access in Motoko incremental garbage collector

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 update: 2025-12-08 Assigner: 6b35d637-e00f-4228-858c-b20ad6e1d07b Source: 6b35d637-e00f-4228-858c-b20ad6e1d07b
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2024-11991 is rated Low Risk (36.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.18%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2024-11991

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-01-18 0.07% 0.18% +0.11%
2 2025-11-21 0.20% 0.07% -0.13%
3 2025-11-18 — 0.20% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-11991

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.6 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 2.2 3.4 6b35d637-e00f-4228-858c-b20ad6e1d07b
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 2.5 [email protected]

Weakness enumeration for CVE-2024-11991

Affected software / configurations for CVE-2024-11991

Vendor Product Version Raw CPE
dfinity motoko >= 0.9.0, < 0.13.4 cpe:2.3:a:dfinity:motoko:*:*:*:*:*:*:*:*

References for CVE-2024-11991

cvelogic Threat Intelligence