Aliasing violations in splice, mutable iteration and cursors

Exploitation

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

CVSS 4.0

2.1 · CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N · score source

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Four code paths create a pointer whose permission is later revoked, then write through it. Miri reports each as undefined behaviour under both the Tree Borrows and Stacked Borrows aliasing models (CWE-758). All four are reachable from safe code with standard `Ord` types. 1. Splice back-pointer. `split_off`, `split_off_index` and `append` stored the first spliced node's `prev` pointer from a reference to the head, then wrote through that same reference, invalidating the stored pointer. A later `pop_first` or `pop_front` writes through it. This affects all four collections. 2. `SkipMap::range_mut` back pointer. With an `Included` or `Excluded` upper bound, the back pointer came from a shared reference. `next_back` hands out `&mut V` through it, and writing to that value is undefined behaviour. 3. `IterMut::next_back` reads a yielded node. In `SkipList` and `SkipMap`, `next_back` read the predecessor node even after the front end had yielded it as `&mut`. The read freezes…

Published by the source

24 Oct 2026, 12:00 UTC

Last modified by the source

26 Oct 2026, 14:00 UTC

Source last checked

27 Oct 2026, 06:25 UTC

1. Revision 1 · created · 27 Oct 2026

   Published from osv record RUSTSEC-2026-0408

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# Patch Next advisory brief: GHSA-924w-mwc9-86m8

Advisory: Aliasing violations in splice, mutable iteration and cursors
IDs: GHSA-924w-mwc9-86m8
Record: https://patchnext.com/advisories/rustsec-2026-0408 (revision 1, source checked 27 Oct 2026, 06:25 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 2.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: skiplist 1.3.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io skiplist: affected >= 0.0.0-0, < 1.3.0; fixed in 1.3.0

## Suggested inspection (read-only)
- crates.io skiplist: 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 skiplist.
- 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-2026-0408 (OSV record RUSTSEC-2026-0408 lists affected ranges: crates.io skiplist >=0.0.0-0 <1.3.0 (fixed))

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