{"schema_version":"1.7.5","id":"GHSA-47q9-m4ww-924m","published":"2026-06-25T21:33:36Z","modified":"2026-07-07T16:11:31.440227368Z","aliases":["CVE-2026-48702","GO-2026-5778"],"related":["CGA-6mjq-v293-wr6f"],"summary":"Rekor has an OOM Condition due to Unbounded gzip Decompression in Alpine APK Parsing Logic","details":"## Description\n\nThe `Package.Unmarshal()` function in `pkg/types/alpine/apk.go` decompresses the signature and control gzip members of an APK file into in-memory buffers without bounding the total decompressed size. The existing `max_apk_metadata_size` check (default 1MB) is only applied to individual tar entry header sizes after decompression completes, so it does not prevent a decompression bomb from consuming unbounded heap memory.\n\nAn attacker can craft a gzip stream that compresses at a ~1000:1 ratio (e.g., 2MB compressed zeros → 2GB decompressed). When submitted as spec.package.content in an Alpine `ProposedEntry`, the server decompresses the full payload into memory during request processing, triggering a fatal Go runtime out-of-memory error or OS OOM-kill that cannot be caught by the server's recover() middleware.\n\nThis is reachable via two unauthenticated endpoints:\n- POST /api/v1/log/entries (createLogEntry)\n- POST /api/v1/log/entries/retrieve (searchLogQuery)\n\nBoth invoke `V001Entry.Canonicalize()` → `fetchExternalEntities()` → `apk.Unmarshal(packageData)`, which performs the unbounded decompression.\n\n## Workarounds\n\nThere is no effective workaround. Setting `max_request_body_size` reduces but does not eliminate exposure due to the ~1000:1 compression ratio (a 1MB body limit still allows ~1GB heap allocation). Setting `max_apk_metadata_size` has no effect on this vulnerability since the check is applied after decompression.","affected":[{"package":{"name":"github.com/sigstore/rekor","ecosystem":"Go","purl":"pkg:golang/github.com/sigstore/rekor"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.3.0"},{"fixed":"1.5.2"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-47q9-m4ww-924m/GHSA-47q9-m4ww-924m.json"}}],"references":[{"type":"WEB","url":"https://github.com/sigstore/rekor/security/advisories/GHSA-47q9-m4ww-924m"},{"type":"PACKAGE","url":"https://github.com/sigstore/rekor"}],"database_specific":{"cwe_ids":["CWE-770"],"github_reviewed":true,"github_reviewed_at":"2026-06-25T21:33:36Z","nvd_published_at":null,"severity":"HIGH"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}