CVE-2025-49844: Redis Lua Use-After-Free may lead to remote code execution

Should you act?

High exploit likelihood

EPSS ranks it in the top 5% of all CVEs for likely exploitation in the next 30 days. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
• EPSS 82.3%, percentile 99.7: FIRST’s model estimates a 82.3% chance of exploitation activity in the next 30 days, higher than 99.7% of all scored CVEs (very high). EPSS is a probability, not a verdict.
• Needs an account (low (any account)). Exposure depends on who can log in.
• Editorial verdict: Patch this week. RediShell: 13-Year-Old Lua Use-After-Free RCE in Redis — Exploitation needs an authenticated session, so properly locked-down Redis can be patched in a normal urgent window; instances reachable without a password are effectively unauthenticated RCE and should be fixed today.

What it is

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.

Weakness type: CWE-416.

Product: redis redis · Assigned by: GitHub_M · Published: 2025-10-03

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: low (any account)
• User interaction: none
• Scope: changed (can affect other components)

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation poc, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 82.29% probability of exploitation activity in the next 30 days; percentile 99.7.

Timeline

• 2025-10-03 — CVE record published by GitHub_M
• 2025-10-03 — erroneo.us brief: RediShell: 13-Year-Old Lua Use-After-Free RCE in Redis
• 2026-03-20 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. CVE.org record CVE-2025-49844 cve.org
2. NVD entry CVE-2025-49844 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com
4. github.com github.com
5. openwall.com openwall.com

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