# CVE-2026-46689: Kanidm: Unauthenticated process abort via SCIM filter stack exhaustion > Unauthenticated attackers can crash the Kanidm identity server by sending SCIM requests with deeply nested parentheses, causing a stack overflow. - **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 10 Jun 2026 - **Updated:** 11 Jun 2026 - **Also known as:** GHSA-r5fr-9gmv-jggh ## What is CVE-2026-46689? CVE-2026-46689 is a high-severity denial of service vulnerability in kanidm, published on 10 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description Kanidm is an identity management platform. Prior to version 1.9.3, 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 extractor, before any handler body and therefore before any ACL check. This issue has been patched in version 1.9.3. Weakness: CWE-674 (Uncontrolled Recursion), CWE-400 (Uncontrolled Resource Consumption), CWE-248 (Uncaught Exception) ## Which versions are affected by CVE-2026-46689? 4 open source packages ship an affected version, including kanidm_proto and scim_proto. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `kanidm_proto` | crates.io | All versions | 1.9.3 | | `kanidm_proto` | crates.io | All versions | 1.9.3 | | `scim_proto` | crates.io | All versions | 1.9.3 | | `scim_proto` | crates.io | All versions | 1.9.3 | ## How do I fix CVE-2026-46689? Upgrade kanidm_proto to 1.9.3 or later. ## Is CVE-2026-46689 being exploited? It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-46689 exists. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-46689 and fix it if it is affected. What it is: CVE-2026-46689 is a high-severity denial of service vulnerability in kanidm, published on 10 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-46689 exists. Affected packages and fixed versions: - kanidm_proto (crates.io): affected all versions; fixed in 1.9.3 - kanidm_proto (crates.io): affected all versions; fixed in 1.9.3 - scim_proto (crates.io): affected all versions; fixed in 1.9.3 - scim_proto (crates.io): affected all versions; fixed in 1.9.3 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-46689/ (Markdown: https://insights.sbomify.com/CVE-2026-46689/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46689 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46689 - OSV: https://osv.dev/vulnerability/CVE-2026-46689 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-46689/ Summaries are generated and may contain mistakes; the official description above is the record.