Panic-safety unsoundness in Stack::pop, Fifo::pop_front and Value::replace_stable (use-after-free / double-free)

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

not scored

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Three removal and replacement paths destroy an initialized value before committing the metadata change that removes it. Destruction runs `T::drop()`, which is user code and may panic. If it does, the commit is skipped and the container still claims ownership of the already-destroyed value, so its own destructor drops that value a second time. `Stack::pop` drops the top value before reducing `next_ofs`. `Stack`'s destructor pops in a loop, so an unchanged `next_ofs` re-drops the same value. `Fifo::pop_front` (via `pop_front_inner`) drops the front value before advancing `read_pos`. An unchanged `read_pos` still points at the destroyed value. `Value::replace_stable` drops the existing value before writing the replacement. If the destructor panics the replacement is never written, but the backing storage still holds the old value's metadata. This is separate from RUSTSEC-2021-0033, which covered a clone panic on insertion in `push_cloned` and was fixed in 0.6.1.

Impact A heap-owning…

Published by the source

27 Aug 2026, 12:00 UTC

Last modified by the source

31 Aug 2026, 09:45 UTC

Source last checked

23 Oct 2026, 22:04 UTC

1. Revision 1 · created · 24 Oct 2026

   Published from osv record RUSTSEC-2026-0272

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# Patch Next advisory brief: rustsec-2026-0272

Advisory: Panic-safety unsoundness in `Stack::pop`, `Fifo::pop_front` and `Value::replace_stable` (use-after-free / double-free)
IDs: rustsec-2026-0272
Record: https://patchnext.com/advisories/rustsec-2026-0272 (revision 1, source checked 23 Oct 2026, 22:04 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Unrated
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: stack_dst 0.8.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io stack_dst: affected >= 0.0.0-0, < 0.8.2; fixed in 0.8.2

## Suggested inspection (read-only)
- crates.io stack_dst: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on stack_dst.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/RUSTSEC-2026-0272 (OSV record RUSTSEC-2026-0272 lists affected ranges: crates.io stack_dst >=0.0.0-0 <0.8.2 (fixed))

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