Use After Free in Lfprojects Valkey
CVE-2025-49844
Redis is an open source, in-memory database that persists on disk. Versions 8.2.1 and below allow an authenticated user to use a specially crafted Lua script to manipulate the garbage collector, trigger a use-after-free and potentially lead to remote code execution. The problem exists in all versions of Redis with Lua scripting. This issue is fixed in version 8.2.2. To workaround this issue without patching the redis-server executable is to prevent users from executing Lua scripts. This can be done using ACL to restrict EVAL and EVALSHA commands.
Vulnerability class: Use-After-Free
EPSS: 0.823 (99.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.
Affected products
- Lfprojects Valkey
- Redis — versions < 8.2.2
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0
Frequently asked questions
- What is CVE-2025-49844?
- CVE-2025-49844 is a critical-severity vulnerability in Lfprojects Valkey, classified under Use After Free. CVSS score: 9.9/10. Published 2025-10-03.
- How severe is CVE-2025-49844?
- Critical severity. CVSS v3 base score is 9.9 out of 10.
- Is CVE-2025-49844 known to be exploited?
- 36 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.