{"id":"GHSA-47q9-m4ww-924m","revision":"456add7aca354012965acc51630577e2","records":[{"revision":"456add7aca354012965acc51630577e2","observedAt":"2026-10-24T13:19:41.952+00:00","statement":{"source":"osv","id":"GHSA-47q9-m4ww-924m","aliases":["CVE-2026-48702","GO-2026-5778"],"title":"Rekor has an OOM Condition due to Unbounded gzip Decompression in Alpine APK Parsing Logic","description":"## 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.","state":0,"publishedAt":"2026-06-25T21:33:36+00:00","modifiedAt":"2026-09-10T03:51:07.8186042+00:00","affected":[{"ecosystem":"Go","name":"github.com/sigstore/rekor","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0.3.0"},{"kind":"fixed","version":"1.5.2"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"HIGH"}],"references":["https://github.com/sigstore/rekor/security/advisories/GHSA-47q9-m4ww-924m","https://github.com/sigstore/rekor"],"sourceUrl":"https://github.com/advisories/GHSA-47q9-m4ww-924m","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-47q9-m4ww-924m","identifiers":["GHSA-47q9-m4ww-924m","CVE-2026-48702","GO-2026-5778"]},"retained":false,"historicalAffected":[]}],"coverage":[]}