GHSA-Q2PW-XX38-P64J
Vulnerability from github – Published: 2026-04-23 21:54 – Updated: 2026-04-27 16:35Impact
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.
Patches
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).
Workarounds
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.
Credits
melange thanks Oleh Konko (@1seal from 1seal.org) for discovering and reporting this issue.
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "chainguard.dev/melange"
},
"ranges": [
{
"events": [
{
"introduced": "0.32.0"
},
{
"fixed": "0.43.4"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-29051"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2026-04-23T21:54:10Z",
"nvd_published_at": "2026-04-24T00:16:27Z",
"severity": "LOW"
},
"details": "### Impact\n\n`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-\u003cpkgname\u003e-\u003cpkgver\u003e-r\u003cepoch\u003e.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.\n\n### Patches\n\nFixed in melange **v0.43.4** by validating `arch` and `pkgname` for `..`, `/`, and `filepath.Separator` before path construction in `pkg/linter/results.go` (commit [84f3b45](https://github.com/chainguard-dev/melange/commit/84f3b450ce6e472c4abb8dc4c26d0ce8ac1259ac)).\n\n### Workarounds\n\nDo 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.\n\n### Credits\n\nmelange thanks Oleh Konko ([@1seal](https://github.com/1seal) from [1seal.org](https://1seal.org/)) for discovering and reporting this issue.",
"id": "GHSA-q2pw-xx38-p64j",
"modified": "2026-04-27T16:35:07Z",
"published": "2026-04-23T21:54:10Z",
"references": [
{
"type": "WEB",
"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": "WEB",
"url": "https://github.com/chainguard-dev/melange/commit/84f3b450ce6e472c4abb8dc4c26d0ce8ac1259ac"
},
{
"type": "PACKAGE",
"url": "https://github.com/chainguard-dev/melange"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N",
"type": "CVSS_V3"
}
],
"summary": "melange has Path Traversal via .PKGINFO in --persist-lint-results"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.