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NVD / CVE Program· CNA GitHub_M

CVE-2026-21863: Malformed Valkey Cluster bus message can lead to Remote DoS

Noroxi assessment

Priority: Monitor (action score 30/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.84% (FIRST EPSS); higher than 58.2% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: azl3 valkey 8.0.6-1 on Azure Linux 3.0 8.0.7-1.

Low priority for now. Upgrade to azl3 valkey 8.0.6-1 on Azure Linux 3.0 8.0.7-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.5 · v3.1—No exploit Fix available
Published
Feb 23, 2026
Updated
Jul 15, 2026
EPSS
0.8% · 58th percentile

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.8%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
7.5
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-21863

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
lfprojectsvalkey

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • lfprojects valkeybefore 7.2.12
  • lfprojects valkey8.0.0 and later · before 8.0.7
  • lfprojects valkey8.1.0 and later · before 8.1.6
  • lfprojects valkey9.0.0 and later · before 9.0.2

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • valkey-io valkey

    • < 7.2.12, >= 8.0.0, < 8.0.7, >= 8.1.0, < 8.1.6, >= 9.0.0, < 9.0.2affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:10valkeybefore 8.0.7-1.el10_18.0.7-1.el10_1
AlmaLinux:10valkey-develbefore 8.0.7-1.el10_18.0.7-1.el10_1
AlmaLinux:9valkeybefore 8.0.7-1.el9_78.0.7-1.el9_7
AlmaLinux:9valkey-develbefore 8.0.7-1.el9_78.0.7-1.el9_7
Alpine:v3.21valkeyfrom 8.0.0 · before 7.2.12-r07.2.12-r0
Alpine:v3.22valkeyfrom 8.0.0 · before 8.1.6-r08.1.6-r0
Alpine:v3.23valkeyfrom 8.0.0 · before 9.0.3-r09.0.3-r0
Debian:12redisbefore 5:7.0.15-1~deb12u75:7.0.15-1~deb12u7
Debian:13redisbefore 5:8.0.2-3+deb13u25:8.0.2-3+deb13u2
Debian:13valkeybefore 8.1.1+dfsg1-3+deb13u28.1.1+dfsg1-3+deb13u2
Debian:14redictbefore 7.3.6+ds-27.3.6+ds-2
Debian:14redisbefore 5:8.0.6-15:8.0.6-1
Debian:14valkeybefore 8.1.4+dfsg1-28.1.4+dfsg1-2
openSUSE:Leap 15.6valkeybefore 8.0.7-150600.13.20.18.0.7-150600.13.20.1
openSUSE:Tumbleweedvalkeybefore 9.0.3-1.19.0.3-1.1
Red Hat:enterprise_linux_eus:10.0valkeybefore 0:8.0.7-1.el10_00:8.0.7-1.el10_0
Red Hat:enterprise_linux_eus:10.0valkey-debuginfobefore 0:8.0.7-1.el10_00:8.0.7-1.el10_0
Red Hat:enterprise_linux_eus:10.0valkey-debugsourcebefore 0:8.0.7-1.el10_00:8.0.7-1.el10_0
Red Hat:enterprise_linux_eus:10.0valkey-develbefore 0:8.0.7-1.el10_00:8.0.7-1.el10_0
Red Hat:enterprise_linux:10.1valkeybefore 0:8.0.7-1.el10_10:8.0.7-1.el10_1
Red Hat:enterprise_linux:10.1valkey-debuginfobefore 0:8.0.7-1.el10_10:8.0.7-1.el10_1
Red Hat:enterprise_linux:10.1valkey-debugsourcebefore 0:8.0.7-1.el10_10:8.0.7-1.el10_1
Red Hat:enterprise_linux:10.1valkey-develbefore 0:8.0.7-1.el10_10:8.0.7-1.el10_1
Red Hat:enterprise_linux:9::appstreamvalkeybefore 0:8.0.7-1.el9_70:8.0.7-1.el9_7

+12

Same product

lfprojects: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-27623Valkey has Pre-Authentication DOS from malformed RESP request
    30Monitor
  • CVE-2025-67733Valkey Affected by RESP Protocol Injection via Lua error_reply
    28Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
azl3 valkey 8.0.6-1 on Azure Linux 3.08.0.7-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
almalinux:valkey8.0.7-1.el10_1 · AlmaLinux:10Package registry (OSV)
almalinux:valkey-devel8.0.7-1.el10_1 · AlmaLinux:10Package registry (OSV)
alpine:valkey7.2.12-r0 · Alpine:v3.21Package registry (OSV)
debian:redict7.3.6+ds-2 · Debian:14Package registry (OSV)
debian:redis5:7.0.15-1~deb12u7 · Debian:12Package registry (OSV)
debian:valkey8.1.1+dfsg1-3+deb13u2 · Debian:13Package registry (OSV)
opensuse:valkey8.0.7-150600.13.20.1 · openSUSE:Leap 15.6Package registry (OSV)
red hat:valkey0:8.0.7-1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:valkey-compat-redis0:9.0.3-1.2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:valkey-compat-redis-devel0:9.0.3-1.2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:valkey-debuginfo0:8.0.7-1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:valkey-debugsource0:8.0.7-1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:valkey-devel0:8.0.7-1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:valkey-doc0:9.0.3-1.2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:valkey-rdma0:9.0.3-1.2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
rocky linux:valkey0:8.0.7-1.el10_1 · Rocky Linux:10Package registry (OSV)
suse:valkey8.0.7-150700.3.14.1 · SUSE:Linux Enterprise Module for Server Applications 15 SP7Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-125 · Out-of-bounds Read

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records