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TI-2026-17565 Aliases CVE-2026-21863

Malformed Valkey Cluster bus message can lead to Remote DoS

Priority MEDIUM 40CWE-125Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-125 and the CVSS impact.

Summary

Valkey is a distributed key-value database. Prior to versions 9.0.2, 8.1.6, 8.0.7, and 7.2.12, a malicious actor with access to the Valkey clusterbus port can send an invalid packet that may cause an out bound read, which might result in the system crashing. The Valkey clusterbus packet processing code does not validate that a clusterbus ping extension packet is located within buffer of the clusterbus packet before attempting to read it. Versions 9.0.2, 8.1.6, 8.0.7, and 7.2.12 fix the issue. As an additional mitigation, don't expose the cluster bus connection directly to end users, and protect the connection with its own network ACLs.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00848 58th percentileScored 2026-11-07
Fix Fixed valkey (valkey-io): 7.2.12, 8.0.7, 8.1.6 +1Red Hat: 4 advisories

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MLflowvalkeybefore 7.2.12; 8.0.0 to before 8.0.7; 8.1.0 to before 8.1.6; 9.0.0 to before 9.0.27.2.12, 8.0.7, 8.1.6, 9.0.2Patch availableCNA
  • valkey VendorMLflow Affected before 7.2.12; 8.0.0 to before 8.0.7; 8.1.0 to before 8.1.6; 9.0.0 to before 9.0.2 Fixed in 7.2.12, 8.0.7, 8.1.6, 9.0.2 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:lfprojects:valkey:*:*:*:*:*:*:*:*before 7.2.12; 8.0.0 to before 8.0.7; 8.1.0 to before 8.1.6; 9.0.0 to before 9.0.2VulnerableMLflow
  • cpe:2.3:a:lfprojects:valkey:*:*:*:*:*:*:*:* Versions before 7.2.12; 8.0.0 to before 8.0.7; 8.1.0 to before 8.1.6; 9.0.0 to before 9.0.2 Vulnerable ·MLflow

Remediation

  • Fix · CNA valkey (valkey-io) Fixed in 7.2.12, 8.0.7, 8.1.6, 9.0.2

Red Hat 4 advisories

  • RHSA-2026:8753 Released 2026-04-17 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images valkey-9.0.3-1.2.hum1@aarch64, valkey-9.0.3-1.2.hum1@src, valkey-9.0.3-1.2.hum1@x86_64 +10
  • RHSA-2026:5445 Released 2026-03-23 · Red Hat rating Important
    valkey security update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) valkey-8.0.7-1.el10_0, valkey-devel-8.0.7-1.el10_0
  • RHSA-2026:3507 Released 2026-03-02 · Red Hat rating Important
    valkey security update
    • Red Hat Enterprise Linux AppStream (v. 9) valkey-8.0.7-1.el9_7, valkey-devel-8.0.7-1.el9_7
Show 1 more Red Hat advisories
  • RHSA-2026:3443 Released 2026-02-26 · Red Hat rating Important
    valkey security update
    • Red Hat Enterprise Linux AppStream (v. 10) valkey-8.0.7-1.el10_1, valkey-devel-8.0.7-1.el10_1

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:3443
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:3507
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:5445
Red Hat Hardened ImagesFixed RHSA-2026:8753

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-21863

References

Advisory 1

  • TI-2025-31759 Redis Lua Use-After-Free may lead to remote code execution CVSS 3.1CRITICAL 10.0
  • TI-2025-15565 Redis DoS Vulnerability due to unlimited growth of output buffers abused by unauthenticated client CVSS 3.1HIGH 7.5
  • TI-2026-22005 Valkey has Pre-Authentication DOS from malformed RESP request CVSS 3.1HIGH 7.5
  • TI-2025-41429 Valkey Affected by RESP Protocol Injection via Lua error_reply CVSS 3.1HIGH 8.5

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences