---
id: "bug-1945"
status: "fixed"
status_updated: "2026-10-10"
status_note: ""
component: "apiserver"
severity: "security"
timestamp: "2026-10-10T08:14:59Z"
last_seen: "2026-10-10T08:14:59Z"
occurrences: 1
files: ["src/frontend/apiserver/config/app.yaml", "src/frontend/apiserver/utils/config.go"]
tags: ["apiserver", "security", "jwt"]
related: []
fix_commits: ["19a1a6f0"]
gitea_issue: 376
gitea_synced_status: "fixed"
gitea_synced_hash: "12d5779fe5f2"
---

# bug-1945: apiserver signs and accepts JWTs with the shipped default secret when XCE_JWT_SECRET is unset

## Description
**Observed:** (source reading, `.kiro/reviews/project-gap-review-2026-10-10.md` (P0); to be confirmed by a failing test before the fix)
`config/app.yaml:17` ships the secret `xce-api-key`; `utils/config.go:315-320` uses `XCE_JWT_SECRET` when set and otherwise keeps the default without any warning.

**Expected:** The apiserver never runs with a publicly known signing secret.
**Impact:** Security: anyone can forge tokens for any user on a deployment that did not set the environment variable.
**Found by:** review: `.kiro/reviews/project-gap-review-2026-10-10.md` (P0)
## Environment
- OS: no /etc/os-release; Docker container; NixOS kernel; kernel Linux 6.18.33 x86_64
- libc: glibc 2.42-47 (interpreter /nix/store/wb6rhpznjfczwlwx23zmdrrw74bayxw4-glibc-2.42-47/lib/ld-linux-x86-64.so.2)
- Toolchain: gcc (GCC) 15.2.0, meson 1.9.1
- Build: asan (xce.build)
- Code: scheduler-framework @ 94472ee3-dirty
- Deployment: any (found by source reading; the failing test that confirms it is named in Verification)

## Reproduction
1. Start the apiserver without `XCE_JWT_SECRET`.
2. Sign a token with `xce-api-key` for user `admin`: it is accepted.
- Frequency: deterministic (by code reading; confirmed by the RED test of the fix)
- Evidence: the code sites quoted in Description; no logs kept.
## Root cause
`resolveJWTSecret()` (`utils/config.go`) fell back to the shipped `xce-api-key` when `XCE_JWT_SECRET` was unset.

## Fix
Empty or the old default secret (env or config) counts as unset: the apiserver generates a random 256-bit per-process secret and logs a warning (tokens do not survive restart; apiservers behind one endpoint must share `XCE_JWT_SECRET`); the secret is never logged; `app.yaml` ships `secretKey: ""`. Docs updated in 27ef5060.

## Verification
- Test: `TestResolveJWTSecret_NeverUsesKnownDefaultOrEmpty`, `TestShippedAppYAML_NoJWTSecret`, `TestInitConf_NoJWTSecretGeneratesAndWarns` (`utils/config_test.go`): RED (`... = "xce-api-key": must be a generated secret`), GREEN after.
- Suites: `xce-build.sh all asan xce.build --incremental` on the merged branch, 2026-10-10: all C suites Ok 155 / Fail 0, frontend Go unit tests ok, xceadmin tests ok; apiserver `CGO_ENABLED=0 go test ./...` (incl. middleware, router, cmd) ok
- Live: n/a: unit/fixture-level verification only; no live deployment was run (follow-up)

## References
- Fix commit: `19a1a6f0` (on `scheduler-framework`; worker-branch original in the merge)
- Review: `.kiro/reviews/project-gap-review-2026-10-10.md`
- docs: 27ef5060