Russh: Unchecked CryptoVec allocation and growth handling is reachable

Exploitation

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

CVSS

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

EPSS

• CVE-2026-46673: 0.26% estimated exploitation activity in the next 30 days; percentile 18.15 (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.

Title Unchecked CryptoVec allocation and growth handling was reachable from local agent inputs in current russh releases and from remote SSH traffic in historical pre-0.58.0 releases Summary CryptoVec used unchecked capacity growth, unchecked length arithmetic, and unsafe allocation/locking paths. In current russh releases, local SSH agent peers could still feed attacker-controlled frame lengths into buffer growth before validation. In older russh releases before 0.58.0, remote SSH traffic also reached CryptoVec through transport and compression buffers. Details The underlying unsafe paths were in CryptoVec: - cryptovec/src/cryptovec.rs - unchecked capacity growth - unchecked length arithmetic in growth callers - raw allocation and reallocation paths coupled to those sizes - cryptovec/src/platform/unix.rs - mlock / munlock previously accepted zero-length calls and performed null-pointer validation inside the unsafe OS-call path There are two relevant reachability stories: 1. current…

Published by the source

21 May 2026, 20:49 UTC

Last modified by the source

11 Jun 2026, 14:06 UTC

Source last checked

26 Oct 2026, 15:42 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-g9f8-wqj9-fjw5

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# Patch Next advisory brief: CVE-2026-46673

Advisory: Russh: Unchecked CryptoVec allocation and growth handling is reachable
IDs: CVE-2026-46673, GHSA-g9f8-wqj9-fjw5
Record: https://patchnext.com/advisories/cve-2026-46673 (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 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: russh-cryptovec 0.60.3; russh 0.60.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io russh-cryptovec: affected <= 0.60.2; fixed in 0.60.3
- crates.io russh: affected <= 0.60.2; fixed in 0.60.3

## Suggested inspection (read-only)
- crates.io russh-cryptovec: check the installed version with your package manager.
- crates.io russh: 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 russh-cryptovec, russh.
- 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-g9f8-wqj9-fjw5 (GitHub-reviewed advisory GHSA-g9f8-wqj9-fjw5 lists affected ranges: crates.io russh-cryptovec >=0 =0 <=0.60.2)

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