CVE-2026-105768: CWE-197 Numeric Truncation Error in chainguard-dev apko
Description
apko allows users to build and publish OCI container images built from apk packages. From version 0.2.0 to before version 1.4.5, UserEntry.Parse and GroupEntry.Parse in pkg/passwd read the UID and GID fields of /etc/passwd and /etc/group entries with strconv.Atoi and convert them to uint32 without a range check. On 64-bit platforms an out-of-range value such as 4294967296 (2^32) is truncated to 0, and negative values wrap. Because apko parses the passwd and group entries supplied by the packages it installs and writes them back into the image, an attacker who controls a package installed into the image can ship an entry that appears to declare an unprivileged UID or GID but is written into the built image as UID 0 or GID 0 (root). The truncated UID is also used when resolving the image's run-as user. This issue has been fixed in version 1.4.5.
CVSS v4.0
Score 6.3medium
Affected software
chainguard-dev
apko
Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- chainguard
- Date Reserved
- 2026-10-05T19:21:04.930Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ac415482cdf04f6563b29ec
Added to database: 10/05/2026, 21:23:20 UTC
Last updated: 10/05/2026, 21:23:20 UTC
Views: 1
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.