[munimv2]

One advisory for cap-primitives, from the critical GitHub security advisory GHSA-hp8f-xmx4-4qrg that @sunfishcode published on 2026-08-20 together with the 3.4.6 and 4.0.3 releases. Wasmtime's advisory for the same bug is already RUSTSEC-2026-0269 (filed under wasmtime), but cap-primitives itself has no entry, so cargo-audit does not warn projects that use cap-std or cap-primitives directly. GitHub has not reviewed GHSA-hp8f either (github.com/advisories/GHSA-hp8f-xmx4-4qrg returns 404 today).

Affected crate(s)

• cap-primitives (the code is there; the GitHub advisory also names cap-std, which depends on it, so a lockfile with cap-std always has cap-primitives too). Filed under cap-primitives like RUSTSEC-2024-0445.

Links to upstream issue(s) or PR(s)

• GHSA-hp8f-xmx4-4qrg (no CVE). Fix: Fix trailing-slash behavior with O_NOFOLLOW. sunfishcode/cap-std#419 and Translate database into V3 advisory format #420 on main, released in 4.0.3; backport 3979d35 (CI: use rustsec-admin v0.3.0-pre in assign-ids step #421), released in 3.4.6. Both releases were published on crates.io on 2026-08-20.
• The GitHub advisory lists <= 4.0.2 as affected and 4.0.3 and 3.4.6 as patched, so patched = [">= 3.4.6, < 4.0.0", ">= 4.0.3"].

Severity

Critical in the GitHub advisory (CVSS 3.1 9.0, included in the file). A symlink inside the sandbox that points outside it is followed when the path, or the symlink's own target, ends in /, which gives read and write access outside the sandboxed directory. This affects Windows and macOS, FreeBSD without O_RESOLVE_BENEATH, and Linux when openat2 is unavailable (kernels before 5.6, or seccomp policies that reject it).

Checklist

• Advisory filename(s) starts with RUSTSEC-0000-0000 as the ID
• date field is set to the public disclosure date
• Contains a concise and descriptive title after advisory metadata
• Asked maintainer(s) if publishing an advisory is appropriate: not asked separately. The advisory and the fixes were both published by the maintainer. @sunfishcode, please say if you'd rather it stay out of RustSec.

The description was written for this PR rather than copied from the GitHub advisory, so the file stays CC0.

Disclosure: this advisory was prepared with AI agents working for MV2 of Munim, Inc., from the upstream advisory, the fix commits and crates.io.
MV2, Munim, Inc. (mv2@munimtech.com)