{"id":"CVE-2026-29051","aliases":["GHSA-q2pw-xx38-p64j","GO-2026-5562"],"url":"https://o3.security/vulnerability/CVE-2026-29051","summary":"melange has Path Traversal via .PKGINFO in --persist-lint-results","details":"melange allows users to build apk packages using declarative pipelines. Starting in version 0.32.0 and prior to version 0.43.4, `melange lint --persist-lint-results` (opt-in flag, also usable via `melange build --persist-lint-results`) constructs output file paths by joining `--out-dir` with the `arch` and `pkgname` values read from the `.PKGINFO` control file of the APK being linted. In affected versions these values were not validated for path separators or `..` sequences, so an attacker who can supply an APK to a melange-based lint/build pipeline (e.g. CI that lints third-party APKs, or build-as-a-service) could cause melange to write `lint-<pkgname>-<pkgver>-r<epoch>.json` to an arbitrary `.json` path reachable by the melange process. The written file is a JSON lint report whose content is partially attacker-influenced. There is no direct code-execution path, but the write can clobber other JSON artifacts on the filesystem. The issue only affects deployments that explicitly pass `--persist-lint-results`; the flag is off by default. The issue is fixed in melange v0.43.4 by validating `arch` and `pkgname` for `..`, `/`, and `filepath.Separator` before path construction in `pkg/linter/results.go` (commit 84f3b45). As a workaround, do not pass `--persist-lint-results` when linting or building APKs whose `.PKGINFO` contents are not fully trusted. Running melange as a low-privileged user and confining writes to an isolated directory also limits impact.","published":"2026-04-24T00:00:36.253Z","modified":"2026-07-31T18:30:44.609325639Z","cvss":{"score":4.4,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"chainguard.dev/melange","fixedVersion":"0.43.4"}],"fix":{"url":"https://github.com/chainguard-dev/melange/commit/84f3b450ce6e472c4abb8dc4c26d0ce8ac1259ac","label":"chainguard-dev/melange@84f3b45"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/29xxx/CVE-2026-29051.json"},{"type":"ADVISORY","url":"https://github.com/chainguard-dev/melange/security/advisories/GHSA-q2pw-xx38-p64j"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-29051"},{"type":"FIX","url":"https://github.com/chainguard-dev/melange/commit/84f3b450ce6e472c4abb8dc4c26d0ce8ac1259ac"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-31T18:30:44.609325639Z"}}