CVE-2026-81934

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Use-After-Free in Redis TLS Processing

Publication date: 2026-08-27

Last updated on: 2026-08-31

Assigner: Cybersecurity and Infrastructure Security Agency (CISA) U.S. Civilian Government

Description

Redis contains a use-after-free vulnerability in the 'tlsProcessPendingData()' function, which handles the TLS pending-data list if Redis is configured with TLS support. A remote, unauthenticated attacker may be able to execute arbitrary commands with the privileges of the Redis server.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-08-27

Last Modified

2026-08-31

Generated

2026-09-17

AI Q&A

2026-08-28

EPSS Evaluated

2026-09-15

NVD

CVE-2026-81934

Affected Vendors & Products

Vendor	Product	Version / Range
redis	redis	8.2.9
redis	redis	8.4.6
redis	redis	8.6.6
redis	redis	8.8.2
redis	redis	8.10.1
redislabs	redis	8.2.9
redislabs	redis	8.4.6
redislabs	redis	8.6.6
redislabs	redis	8.8.2
redislabs	redis	8.10.1

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-416	The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Attack-Flow Graph

Executive Summary

Redis contains a use-after-free vulnerability in the 'tlsProcessPendingData()' function when TLS is enabled. The function uses an iterator to process TLS pending connections. If a connection is closed during processing, the iterator may reference freed memory, causing a crash or allowing arbitrary command execution with Redis server privileges.

Detection Guidance

Detecting this vulnerability requires checking Redis server version and configuration. Use commands like 'redis-cli info server' to check the version. If using TLS, inspect the server logs for crashes or SIGSEGV errors during TLS operations. Monitor for unexpected command execution or unusual activity in Redis logs.

Impact Analysis

An unauthenticated remote attacker could exploit this to execute arbitrary commands as the Redis server process. This could lead to data theft, unauthorized modifications, or denial of service by crashing the Redis server. Systems using Redis with TLS support are at risk.

Compliance Impact

This vulnerability could lead to unauthorized data access or modification, violating GDPR's integrity and confidentiality requirements or HIPAA's safeguards for protected health information. Organizations must patch Redis to maintain compliance.

Mitigation Strategies

Upgrade Redis to a fixed version (8.2.9, 8.4.6, 8.6.6, 8.8.2, or 8.10.1 or later). If upgrading is not immediately possible, disable TLS support in Redis configuration to reduce attack surface. Restrict network access to Redis instances using firewalls.

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