Memory corruption slice-deque

Exploitation

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

CVSS

9.8 · CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2018-20995: 1.61% estimated exploitation activity in the next 30 days; percentile 75.98 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Affected versions of this crate did not properly update the head and tail of the deque when inserting and removing elements from the front if, before insertion or removal, the tail of the deque was in the mirrored memory region, and if, after insertion or removal, the head of the deque is exactly at the beginning of the mirrored memory region. An attacker that controls both element insertion and removal into the deque could put it in a corrupted state. Once the deque enters such an state, its head and tail are corrupted, but in bounds of the allocated memory. This can result in partial reads and writes, reads of uninitialized memory, reads of memory containing previously dropped objects, etc. An attacker could exploit this to alter program execution. The flaw was corrected by properly updating the head and tail of the deque in this case.

Published by the source

25 Aug 2021, 20:42 UTC

Last modified by the source

13 Jun 2023, 20:55 UTC

Source last checked

26 Oct 2026, 15:34 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-hr3c-6mmp-6m39

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# Patch Next advisory brief: CVE-2018-20995

Advisory: Memory corruption slice-deque
IDs: CVE-2018-20995, GHSA-hr3c-6mmp-6m39
Record: https://patchnext.com/advisories/cve-2018-20995 (revision 1, source checked 26 Oct 2026, 15:34 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: slice-deque 0.1.16. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io slice-deque: affected < 0.1.16; fixed in 0.1.16

## Suggested inspection (read-only)
- crates.io slice-deque: 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 slice-deque.
- 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://github.com/advisories/GHSA-hr3c-6mmp-6m39 (GitHub-reviewed advisory GHSA-hr3c-6mmp-6m39 lists affected ranges: crates.io slice-deque >=0 <0.1.16)

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