scim_proton and kanidm_proto have an authenticated process abort via SCIM filter stack exhaustion — CVE-2026-46689

Summary

### Summary A single unauthenticated `GET` to any `/scim/v1/...` endpoint with a `?filter=` query string of a few thousand nested parentheses (≈ 4–12 KB) drives the recursive-descent PEG parser past the worker thread's stack guard page. Rust responds to stack overflow with `std::process::abort()` — the entire `kanidmd` process exits. The parse runs inside axum's `Query<ScimEntryGetQuery>` extractor, before any…

Product

rust: scim_proto | rust: kanidm_proto

What to do

General, cautious steps (verify details in the official source):

• Prioritize patching or mitigation immediately (treat as actively risky).
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

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