{"id":"GHSA-98f2-w9h9-7fp9","summary":"melange has Path Traversal When Resolving External Pipelines via Unvalidated pipeline[].uses","details":"### Impact\n\nAn attacker who can influence a melange configuration file — for example through pull-request-driven CI or build-as-a-service scenarios — could set `pipeline[].uses` to a value containing `../` sequences or an absolute path. The `(*Compiled).compilePipeline` function in `pkg/build/compile.go` passed `uses` directly to `filepath.Join(pipelineDir, uses + \".yaml\")` without validating the value, so the resolved path could escape each `--pipeline-dir` and read an arbitrary YAML-parseable file visible to the melange process. Because the loaded file is subsequently interpreted as a melange pipeline and its `runs:` block is executed via `/bin/sh -c` in the build sandbox, this additionally allowed shell commands sourced from an out-of-tree file to run during the build, bypassing the review boundary that normally covers the in-tree pipeline definition.\n\n### Patches\n\nFixed in melange **v0.43.4** via commit [5829ca4](https://github.com/chainguard-dev/melange/commit/5829ca45cfe14dfeb73ffb716992db3b1b7892ac). The fix rejects `uses` values that are absolute paths or contain `..`, and verifies (via `filepath.Rel` after `filepath.Clean`) that the resolved target remains within the pipeline directory.\n\n### Workarounds\n\nOnly run `melange build` against configuration files from trusted sources. In CI systems that build user-supplied melange configs, gate builds behind manual review of `pipeline[].uses` values and reject any containing `..` or leading `/`.\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.","aliases":["CVE-2026-29050","GO-2026-5279"],"modified":"2026-06-25T19:56:13.113190244Z","published":"2026-04-23T21:53:33Z","database_specific":{"github_reviewed_at":"2026-04-23T21:53:33Z","nvd_published_at":"2026-04-24T00:16:27Z","cwe_ids":["CWE-22"],"severity":"MODERATE","github_reviewed":true},"references":[{"type":"WEB","url":"https://github.com/chainguard-dev/melange/security/advisories/GHSA-98f2-w9h9-7fp9"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-29050"},{"type":"WEB","url":"https://github.com/chainguard-dev/melange/commit/5829ca45cfe14dfeb73ffb716992db3b1b7892ac"},{"type":"PACKAGE","url":"https://github.com/chainguard-dev/melange"}],"affected":[{"package":{"name":"chainguard.dev/melange","ecosystem":"Go","purl":"pkg:golang/chainguard.dev/melange"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.32.0"},{"fixed":"0.43.4"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-98f2-w9h9-7fp9/GHSA-98f2-w9h9-7fp9.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N"}]}