CVE-2026-86227Public exploitNetwork attack vector

Server crash via unchecked RDB slot ranges

Published Sep 6, 2026 · Updated Sep 9, 2026

Out-of-bounds read in Valkey 9.0.0 through 9.0.5 and 9.1.0 through 9.1.1 allows attackers to crash the server during startup. clusterRDBLoadSlotImport narrows unvalidated 64-bit slot bounds into signed integers; kvstoreGetHashtable then uses the negative value as an array index. Reachability requires cluster mode and control of a startup RDB through data-directory write access, a replication feed, or a stored crafted dump.

CVSS severity3.1
Low
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Valkey 9.0.0 through 9.0.5 and 9.1.0 through 9.1.1 allows attackers to crash the server during startup. clusterRDBLoadSlotImport narrows unvalidated 64-bit slot bounds into signed integers; kvstoreGetHashtable then uses the negative value as an array index. Reachability requires cluster mode and control of a startup RDB through data-directory write access, a replication feed, or a stored crafted dump.

The record

CVE
CVE-2026-86227
Published
Sep 6, 2026
Updated
Sep 9, 2026
Vendor
Valkey
Product
Valkey
Classifications
CWE-125, CWE-119, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=9.0.0
  2. Affected versionversion=9.0.1
  3. Affected versionversion=9.0.2
  4. Affected versionversion=9.0.3
  5. Affected versionversion=9.0.4
  6. Affected versionversion=9.0.5
  7. Affected versionversion=9.1.0
  8. Affected versionversion=9.1.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Valkey · Valkeyversion=9.0.0; version=9.0.1; version=9.0.2; version=9.0.3; version=9.0.4; version=9.0.5; version=9.1.0; version=9.1.1

Published CVSS scores

1.3VulDB CNACVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
3.1VulDB CNACVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
2.1VulDB CNAAV:N/AC:H/Au:S/C:N/I:N/A:P
4.7Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-125Out-of-Bounds Read
CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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