Cap'n Proto and its Rust implementation vulnerable to out-of-bounds read due to logic error handling list-of-list

Exploitation

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

CVSS

5.4 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:L

EPSS

• CVE-2022-46149: 0.93% estimated exploitation activity in the next 30 days; percentile 60.75 (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.

The Cap'n Proto library and capnp Rust package are vulnerable to out-of-bounds read due to logic error handling list-of-list. If a message consumer expects data of type "list of pointers", and if the consumer performs certain specific actions on such data, then a message producer can cause the consumer to read out-of-bounds memory. This could trigger a process crash in the consumer, or in some cases could allow exfiltration of private in-memory data. Impact ====== - Remotely segfault a peer by sending it a malicious message, if the victim performs certain actions on a list-of-pointer type. - Possible exfiltration of memory, if the victim performs additional certain actions on a list-of-pointer type. - To be vulnerable, an application must perform a specific sequence of actions, described below. At present, we are not aware of any vulnerable application, but we advise updating regardless. Fixed in ======== Unfortunately, the bug is present in inlined code, therefore the fix will…

Published by the source

5 Dec 2022, 17:58 UTC

Last modified by the source

28 Jan 2023, 05:05 UTC

Source last checked

26 Oct 2026, 15:33 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-qqff-4vw4-f6hx

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# Patch Next advisory brief: CVE-2022-46149

Advisory: Cap'n Proto and its Rust implementation vulnerable to out-of-bounds read due to logic error handling list-of-list
IDs: CVE-2022-46149, GHSA-qqff-4vw4-f6hx
Record: https://patchnext.com/advisories/cve-2022-46149 (revision 1, source checked 26 Oct 2026, 15:33 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: capnp 0.15.2, 0.14.11, 0.13.7. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io capnp: affected >= 0.15.0, < 0.15.2; >= 0.14.0, < 0.14.11; < 0.13.7; fixed in 0.14.11, 0.15.2, 0.13.7

## Suggested inspection (read-only)
- crates.io capnp: 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 capnp.
- 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-qqff-4vw4-f6hx (GitHub-reviewed advisory GHSA-qqff-4vw4-f6hx lists affected ranges: crates.io capnp >=0.15.0 =0.14.0 =0 <0.13.7)

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