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RedisDatabase / datastore

CVE-2026-23479

HIGH · 8.8 CVSS v3.1 Published 2026-05-05
Fix available
A fix is available. Upgrade to 8.6.3 or later.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Redis is an in-memory data structure store. In redis-server from 7.2.0 until 8.6.3, the unblock client flow does not handle an error return from `processCommandAndResetClient` when re-executing a blocked command. If a blocked client is evicted during this flow, an authenticated attacker can trigger a use-after-free that may lead to remote code execution. This has been patched in version 8.6.3.

In the news

Third-party coverage
Trending covered by 1 outlet this week · latest 2mo ago

Surfaced from public web coverage — external links open in a new tab.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

In redis-server versions 7.2.0 through 8.6.2, the unblock client flow fails to properly handle an error return from `processCommandAndResetClient` when re-executing a blocked command. When a blocked client is evicted during this flow, an authenticated attacker can trigger a use-after-free vulnerability that may lead to remote code execution.

MitigationUpgrade redis-server to version 8.6.3 or later to apply the patch that properly handles error returns in the unblock client flow.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
RedisDatabase / datastore
Affected:>= 7.2.0, < 8.6.3

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Determine installed Redis server version
    Run `redis-server --version` or `redis-cli INFO server | grep redis_version`
    Affected if Version is 7.2.0 through 8.6.3 (inclusive of 7.2.0, exclusive of 8.6.3)
  2. Identify if blocking commands are in use
    Run `redis-cli INFO commandstats | grep -E 'cmd=blpop|cmd=brpop|cmd=blmove|cmd=brpoplpush'` to check usage of blocking list commands, or monitor active connections with `redis-cli CLIENT LIST`
    Affected if Applications use blocking commands (BLPOP, BRPOP, BRPOPLPUSH, BLMOVE) and clients can be evicted while blocked
  3. Check client output buffer limits
    Inspect `redis-cli CONFIG GET client-output-buffer-limit` - look for configured client eviction thresholds
    Affected if Client output buffer limits are set that allow client eviction under memory pressure
  4. Verify client authentication is enabled
    Run `redis-cli CONFIG GET requirepass` to check if password authentication is required
    Affected if Authenticated clients can connect (any password set or no password, as attacker needs valid authentication to trigger the flaw)

A user is affected if running Redis 7.2.0-8.6.3 with blocking commands active, authenticated clients present, and client eviction enabled, allowing a blocked client to be evicted during unblock/re-execution flow.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 8.6.3 or later
Fixed in 8.6.3
Interim mitigation

Upgrade redis-server to version 8.6.3 or later to apply the patch that properly handles error returns in the unblock client flow.

Recommended fix High confidence

8.6.3 or later

  1. Upgrade Redis to version 8.6.3 or later. For example, using package manager: `apt-get update && apt-get install redis-server` (Debian/Ubuntu) or `yum update redis` (RHEL/CentOS).
  2. If using a containerized deployment, update the Docker image tag to `redis:8.6.3` or later in your docker-compose.yml or Kubernetes deployment.
  3. After upgrade, restart the Redis service: `systemctl restart redis-server` or `systemctl restart redis`.
  4. Verify Redis is running and the version is correct: `redis-server --version` should show 8.6.3 or higher.
  5. Test that the Redis server is functioning properly: run `redis-cli ping` which should return PONG.
Caveat Review Redis 8.6.3 release notes for any potential breaking changes from your current version, though this is primarily a security patch release.

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Redis Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing3.0 h
  • Review / QA2.0 h
8.0 hours of engineering $1,390
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-23479 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data