Executive Summary

Executive Summary

A high-severity remote code execution (RCE) vulnerability, CVE-2026-25243, has been disclosed in Redis, one of the world's most widely deployed in-memory data stores and caching platforms. The vulnerability resides in the RESTORE command and allows an authenticated attacker with permission to execute the command to trigger unsafe memory operations using a specially crafted serialized payload. Under certain conditions, successful exploitation may result in arbitrary code execution within the context of the redis-server process.

Redis officially disclosed the vulnerability on May 5, 2026, and has released patches across all supported Redis branches. Since the disclosure, public technical analysis and exploit research have become available, increasing the likelihood that attackers will attempt to weaponize the vulnerability against exposed or improperly secured Redis deployments.

Organizations running vulnerable Redis versions should prioritize patching affected systems, review Access Control List (ACL) policies, restrict access to the RESTORE command where possible, and monitor Redis deployments for suspicious administrative activity.

Technical Information

The vulnerability, tracked as CVE-2026-25243, affects multiple supported versions of Redis Community Edition and Redis Software. The issue originates from insufficient validation of serialized data processed by the RESTORE command.

The RESTORE command is designed to recreate Redis keys from previously serialized values and is commonly used during backup restoration, migration, replication testing, and administrative operations. Improper validation of specially crafted serialized objects can result in invalid memory access during the deserialization process.

According to the official Redis security advisory, successful exploitation requires:

• Authentication to the Redis instance.
• Permission to execute the RESTORE command.
• Delivery of a specially crafted serialized payload.

The vulnerability has been assigned:

• CVE: CVE-2026-25243
• CVSS v4.0: 7.7 (High)
• CWE: CWE-122 – Heap-Based Buffer Overflow

Although exploitation requires authenticated access, Redis is frequently deployed in environments where administrative access is overly permissive, increasing the potential exposure of vulnerable systems.

Vulnerability Details

The RESTORE command accepts serialized Redis objects and recreates them within the database. During deserialization, Redis performs multiple validation and parsing operations before reconstructing the object in memory.

CVE-2026-25243 results from insufficient validation of specially crafted serialized input. A malicious payload can trigger invalid memory access during object restoration, potentially leading to memory corruption and, under favorable conditions, arbitrary code execution within the Redis server process.

Public vulnerability analysis classifies the weakness as CWE-122 (Heap-Based Buffer Overflow). While the official advisory describes the issue as an invalid memory access vulnerability, independent technical research has demonstrated that carefully crafted serialized objects can manipulate internal memory structures during the deserialization process.

Unlike vulnerabilities that can be triggered remotely without authentication, exploitation of CVE-2026-25243 requires the attacker to authenticate successfully and possess sufficient privileges to execute the RESTORE command. As a result, environments implementing strong authentication, properly configured ACLs, and network segmentation significantly reduce the attack surface.

Redis has released security updates addressing the vulnerability across all supported release branches. Fixed versions include:

• Redis Community Edition 6.2.22
• Redis Community Edition 7.2.14
• Redis Community Edition 7.4.9
• Redis Community Edition 8.2.6
• Redis Community Edition 8.4.3
• Redis Community Edition 8.6.3

Corresponding updates have also been released for Redis Software, while Redis Cloud deployments were remediated by Redis before the public disclosure.

As an interim mitigation, Redis recommends restricting execution of the RESTORE command through Access Control Lists (ACLs) until affected systems can be upgraded.

Exploitation and Public Research

Redis publicly disclosed CVE-2026-25243 on May 5, 2026, together with patches for all supported Redis release branches. Following the disclosure, security researchers published technical analyses examining the vulnerability and demonstrating how malformed serialized objects supplied through the RESTORE command can trigger unsafe memory operations during deserialization.

Subsequent independent security research has resulted in publicly available proof-of-concept (PoC) code demonstrating exploitation against vulnerable Redis versions under controlled laboratory conditions. The published research describes an exploitation chain that leverages crafted serialized objects to manipulate memory during the deserialization process and ultimately achieve arbitrary code execution. While these demonstrations show that reliable exploitation is technically possible, they are based on researcher-controlled environments and should not be interpreted as evidence of widespread exploitation in production environments.

As of July 23, 2026, there is no public confirmation from Redis, CISA, or the National Vulnerability Database (NVD) indicating that CVE-2026-25243 has been actively exploited in the wild. However, the availability of detailed technical analysis and public exploit code significantly lowers the barrier for attackers seeking to weaponize the vulnerability. Organizations should therefore assume that exploit attempts are likely to increase over time, particularly against exposed Redis instances or environments with weak administrative controls.

Attack Prerequisites and Impact

Successful exploitation of CVE-2026-25243 requires several conditions to be met.

An attacker must:

• Obtain authenticated access to the Redis instance.
• Have permission to execute the RESTORE command.
• Deliver a specially crafted serialized payload designed to trigger the vulnerability during object deserialization.

These prerequisites reduce the likelihood of opportunistic Internet-wide exploitation compared to unauthenticated remote vulnerabilities. Nevertheless, many Redis deployments are used in internal environments where administrative accounts, overly permissive ACL policies, or trusted network assumptions may increase the attack surface.

If successfully exploited, the vulnerability may allow arbitrary code execution within the security context of the redis-server process. Depending on the deployment architecture and operating system configuration, an attacker could potentially:

• Execute arbitrary commands on the affected host.
• Access sensitive application data stored within Redis.
• Steal credentials, API keys, session tokens, or cached secrets.
• Establish persistence on the compromised server.
• Pivot laterally to other systems within the network.
• Deploy additional malware or ransomware.

The overall business impact depends on how Redis is integrated into the organization's infrastructure. Redis frequently serves as a critical component supporting authentication services, web applications, cloud-native workloads, message queues, session management, caching layers, and distributed microservices. Compromise of a Redis server may therefore affect multiple downstream applications and services.

Detection and Indicators of Compromise

At the time of publication, Redis has not released vulnerability-specific Indicators of Compromise (IOCs) associated with CVE-2026-25243. Likewise, there are currently no publicly documented attack signatures uniquely identifying exploitation of this vulnerability.

Organizations should instead monitor for suspicious administrative activity involving Redis, including:

• Unexpected or unauthorized execution of the RESTORE command.
• RESTORE operations initiated by unusual user accounts or originating from unexpected IP addresses.
• Administrative commands executed outside normal maintenance windows.
• Unexpected Redis crashes, segmentation faults, or abnormal process termination that could indicate failed exploitation attempts.
• Newly created processes running under the redis-server account.
• Unexpected outbound network connections initiated from Redis hosts.
• Unauthorized modifications to Redis configuration files, ACL policies, or persistence settings.
• Creation of unfamiliar scheduled tasks, services, startup scripts, or binaries on systems hosting Redis.

Security teams should also review authentication logs, administrative command history, operating system telemetry, endpoint detection and response (EDR) alerts, and network monitoring data for signs of unauthorized activity involving Redis infrastructure.

Because exploitation requires authenticated access, organizations should pay particular attention to failed authentication attempts, privilege escalation events, and abnormal administrative behavior preceding suspicious Redis activity.

Mitigation and Remediation

Organizations running Redis should prioritize remediation of CVE-2026-25243 by applying the latest security updates released by Redis.

Immediate mitigation actions include:

• Upgrade Redis to a patched release appropriate for your deployment branch. Security fixes are available in:

• Redis Community Edition 6.2.22
• Redis Community Edition 7.2.14
• Redis Community Edition 7.4.9
• Redis Community Edition 8.2.6
• Redis Community Edition 8.4.3
• Redis Community Edition 8.6.3

• If immediate patching is not possible, restrict access to the RESTORE command using Redis Access Control Lists (ACLs), as recommended by Redis.
• Limit network access to Redis servers using firewalls, security groups, or network segmentation. Redis instances should never be directly exposed to untrusted networks unless absolutely necessary.
• Enforce strong authentication and apply the principle of least privilege for all Redis users. Administrative permissions should only be granted to trusted accounts.
• Review ACL configurations and ensure that only authorized administrators can execute high-risk commands such as RESTORE.
• Continuously monitor Redis logs, authentication events, and administrative activity for suspicious behavior or unauthorized command execution.
• If compromise is suspected:

• Isolate the affected Redis instance.
• Perform a forensic investigation to determine the scope of the incident.
• Rotate credentials, API keys, session tokens, and any secrets that may have been stored in or accessible through Redis.
• Review adjacent systems for signs of lateral movement or persistence.

Redis Cloud customers were protected prior to the public disclosure, while customers using Redis Community Edition or Redis Software should verify that all deployments have been updated to supported patched versions.

Threat Landscape and Risk Assessment

Although CVE-2026-25243 requires authenticated access and permission to execute the RESTORE command, it should not be considered a low-risk vulnerability. Redis is widely deployed across enterprise environments as a core component supporting web applications, cloud-native platforms, microservices, authentication systems, and distributed infrastructure. As a result, compromise of a Redis server can have a significant impact beyond the database itself.

The publication of detailed technical analyses and publicly available proof-of-concept research has increased the likelihood that attackers will incorporate this vulnerability into future offensive tooling. While there is no publicly confirmed evidence of active exploitation in the wild as of July 23, 2026, organizations should expect continued security research and potential weaponization, particularly against environments that expose administrative Redis functionality or maintain overly permissive access controls.

Security teams should treat this vulnerability as a high-priority remediation effort, particularly for Internet-facing deployments, production environments, and systems processing sensitive or business-critical information. Organizations should ensure that Redis deployments are patched, properly segmented, protected by strong authentication and ACLs, and continuously monitored for anomalous administrative activity.

References

• Redis Security Advisory – CVE-2026-25243
   https://redis.io/blog/security-advisory-cve202623479-cve202625243-cve-2026-25588-cve202625589-cve-2026-23631/
• GitHub Security Advisory (GHSA-c8h9-259x-jff4)
   https://github.com/redis/redis/security/advisories/GHSA-c8h9-259x-jff4
• National Vulnerability Database (NVD)
   https://nvd.nist.gov/vuln/detail/CVE-2026-25243
• Redis Release Notes
   https://github.com/redis/redis/releases
• ThreatWire Research (X)
   https://x.com/threatwire_/status/2080202269685940460
• Independent Technical Research and Proof-of-Concept
   https://github.com/dinosn/CVE-2026-25243

Rescana is here for you

At Rescana, we understand the critical importance of proactive third-party risk management (TPRM) in today’s rapidly evolving threat landscape. Our advanced TPRM platform empowers organizations to continuously monitor, assess, and mitigate cyber risks across their entire vendor ecosystem. While this advisory focuses on the latest Redis vulnerability, our platform is designed to help you stay ahead of emerging threats, streamline compliance, and build cyber resilience across your supply chain. We are committed to supporting your security and risk management objectives.

If you have any questions about this advisory or require further assistance, please contact us at info@rescana.com.