CVE-2026-105768apko /etc/passwd and /etc/group UID/GID truncation writes package-supplied entries as root
Updated under an hour ago ()
Does this affect you?
It affects chainguard-dev apko. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
Do this next
Free account, 1 product
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
- 6.3 MEDIUM (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N
- Weakness (CWE)
- CWE-197
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- chainguard
- NVD analysis
- Deferred
- Record last updated
- Oct 6, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
chainguard-dev apko chainguard_dev:apko (from the name) | from 0.2.0 before 1.4.5 | CNA record |
References
- https://github.com/chainguard-dev/apko/security/advisories/GHSA-rj6x-hwpv-vhvfvendor-advisory
- https://github.com/chainguard-dev/apko/pull/2516patch
- https://github.com/chainguard-dev/apko/commit/739e7ce3f675ffb232e16849b51ff93657f1570cpatch
- https://github.com/chainguard-dev/apko/releases/tag/v1.4.5release-notes
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.