High, CVSS 8.7crates.ioPublished
scim_proto and kanidm_proto have an authenticated process abort via SCIM filter stack exhaustion
CVE-2026-46689 · GHSA-r5fr-9gmv-jggh
- Affected
- crates.io kanidm_proto <= 1.9.2
- Fixed in
- 1.9.3· Vendor fix available
- Issue
- 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 handler body and therefore before any ACL check. Details The SCIM filter grammar recurses on ( and not ( with no depth bound. proto/src/scimv1/mod.rs:263-433 — peg::parser! { grammar scimfilter() ... }: Both rules re-enter parse() without a depth counter. proto/src/scimv1/mod.rs:442-447 — impl FromStr for ScimFilter calls scimfilter::parse(input) directly on the raw string with no length or depth pre-check. proto/src/scimv1/mod.rs:80-81 — ScimEntryGetQuery.filter is #[serdeas(as = "Option<DisplayFromStr")], so deserialising the query struct invokes ScimFilter::fromstr on attacker bytes.…
Recommended action: Upgrade to 1.9.3 or later, then redeploy and verify.A vendor fix does not resolve your finding until you verify it in your own systems.