High

Use-After-Free RCE in Redis unblock client flow

IdentifiersCVE-2026-23479CWE-416· Use After Free

CVE-2026-23479 is an authenticated use-after-free vulnerability in Redis affecting redis-server from 7.2.0 through 8.6.2. The flaw is in the blocked-client re-execution path, specifically the unblock client flow in src/blocked.c, reported in connection with unblockClientOnKey(). When Redis re-executes a blocked command, it calls processCommandAndResetClient() but does not correctly handle an error return indicating that the client was freed as a side effect. If a blocked client is evicted during this flow, Redis can continue operating on a stale client pointer, creating a use-after-free condition. Public reporting states the bug was introduced by the interaction of 2023 changes and remained present across stable branches until Redis released fixes on May 5, 2026. The vulnerability may be exploitable for remote code execution by an authenticated attacker.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation can lead to remote code execution in the context of the redis-server process. Public exploit analysis describes arbitrary OS command execution on the host by reclaiming freed heap memory with attacker-controlled data and redirecting control flow. Depending on deployment, this can result in full compromise of the Redis instance, access to in-memory data, execution of shell commands as the Redis service account, service disruption, and potential follow-on lateral movement from the affected host.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, reduce exposure by keeping Redis off the public internet, restricting network access to trusted sources, enforcing authentication, enabling protected mode where applicable, tightening ACLs to least privilege, and removing access to risky command categories not required by the workload. The content specifically notes that denying scripting/Lua if unused and restricting administrative capabilities such as CONFIG can hinder the published exploit chain. Using TLS and rotating broadly shared Redis credentials are also recommended hardening steps. These measures mitigate exploitability but do not fully fix the vulnerability.

Remediation

Patch, then assume compromise.

Upgrade Redis to a fixed release. The provided content identifies patched OSS/CE versions as 7.2.14, 7.4.9, 8.2.6, 8.4.3, and 8.6.3; broader Redis advisories in the content also reference 6.2.22 as part of the coordinated security release. For self-managed deployments, move to the latest vendor-fixed version in the relevant branch. Redis Cloud was reported as already patched at publication time. Apply vendor updates rather than relying on configuration-only workarounds, because denying specific commands may disrupt the published exploit chain without removing the underlying memory-safety flaw.

PUBLIC EXPLOITS

Exploits

No valid public exploits. Mallory filtered out 2 candidates as fakes, detection scripts, or README-only repos.

VALID 0 / 2 TOTALView more in app

All candidate exploits were filtered out by Mallory's validation.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

RedisRedisapplication

RedisRedis Softwareapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

48 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

48 SOURCESView more in app

scworldNews

Jun 4, 2026

Critical Redis vulnerability CVE-2026-23479 allows remote code execution | brief | SC Media

A critical remote code execution vulnerability in Redis caused by a use-after-free flaw in unblockClientOnKey() within src/blocked.c, affecting versions since 7.2.0 and requiring an authenticated session with specific ACL privileges.

the hacker newsNews

Jun 3, 2026

Autonomous AI Tool Finds 2-Year-Old RCE Flaw in Redis (CVE-2026-23479)

An authenticated remote code execution vulnerability in Redis caused by a use-after-free in blocking-client code, allowing arbitrary OS command execution on the host running Redis.

cyber security newsNews

May 7, 2026

Critical Redis Vulnerabilities Enables Remote Code Execution Attacks

A use-after-free vulnerability in Redis's unblock client flow that can allow authenticated attackers to achieve remote code execution.

ca ccsNews

May 5, 2026

Redis security advisory (AV26-423) - Canadian Centre for Cyber Security

A Redis vulnerability addressed in a Redis security advisory affecting Redis Software and Redis OSS/CE releases across multiple versions.

+1 more in the timeline

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.

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Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity42

Community discussion across Reddit, Mastodon, and other social sources.

EXTERNAL REFERENCES

MITRE CVE

cve.org · CVE-2026-23479

NVD

nvd.nist.gov/vuln/detail/CVE-2026-23479

MITRE CWE · CWE-416

Use After Free

Vendor Advisory

github.com/redis/redis/security/advisories/GHSA-93m2-935m-8rj3

Release Notes

github.com/redis/redis/releases/tag/8.6.3