rust-openssl has incorrect bounds assertion in aes key wrap

Exploitation

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

CVSS 4.0

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

EPSS

• CVE-2026-41678: 0.25% estimated exploitation activity in the next 30 days; percentile 16.57 (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.

Summary aes::unwrapkey() has an incorrect bounds assertion on the out buffer size, which can lead to out-of-bounds write. Details aes::unwrapkey() contains an incorrect assertion: it checks that out.len() + 8 <= in.len(), but this condition is reversed. The intended invariant is out.len() = in.len() - 8, ensuring the output buffer is large enough. Because of the inverted check, the function only accepts buffers at or below the minimum required size and rejects larger ones. If a smaller buffer is provided the function will write past the end of out by in.len() - 8 - out.len() bytes, causing an out-of-bounds write from a safe public function. Impact Vulnerable applications using AES keywrap and allowing attacker controlled buffer sizes could have an attacker trigger an out-of-bounds write.

Published by the source

22 Apr 2026, 21:17 UTC

Last modified by the source

27 Apr 2026, 16:41 UTC

Source last checked

26 Oct 2026, 15:42 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-8c75-8mhr-p7r9

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# Patch Next advisory brief: CVE-2026-41678

Advisory: rust-openssl has incorrect bounds assertion in aes key wrap
IDs: CVE-2026-41678, GHSA-8c75-8mhr-p7r9
Record: https://patchnext.com/advisories/cve-2026-41678 (revision 1, source checked 26 Oct 2026, 15:42 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.2)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: openssl 0.10.78. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io openssl: affected >= 0.10.24, < 0.10.78; fixed in 0.10.78

## Suggested inspection (read-only)
- crates.io openssl: 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 openssl.
- 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-8c75-8mhr-p7r9 (GitHub-reviewed advisory GHSA-8c75-8mhr-p7r9 lists affected ranges: crates.io openssl >=0.10.24 <0.10.78)

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