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2.2
LOW CVSS 3.1
CVE-2026-82631
valkey-io valkey Blocked-on-keys blocked.c handleClientsBlockedOnKey use after free
Overview
Description

A security flaw has been discovered in valkey-io valkey 9.1.0. The affected element is the function handleClientsBlockedOnKey of the file src/blocked.c of the component Blocked-on-keys Subsystem. The manipulation results in use after free. The attack may be performed from remote. A high complexity level is associated with this attack. The exploitability is described as difficult. The exploit has been released to the public and may be used for attacks. The patch is identified as b2fb0e13f5b4c8c2fb63dcfc2c37a067a0d6d20b. Applying a patch is advised to resolve this issue.

Details
INFO

Published Date :

Aug. 31, 2026, 8:17 a.m.

Last Modified :

Aug. 31, 2026, 8:17 a.m.

Remotely Exploit :

Yes !

Source :

[email protected]
Impact
Affected Products

The following products are affected by CVE-2026-82631 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Valkey-io valkey
: Total Affected Vendor : 1 | Products : 1
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 2.0 LOW [email protected]
CVSS 3.1 LOW [email protected]
CVSS 4.0 LOW [email protected]
Solution
Resolve use-after-free by applying the provided patch to the Blocked-on-keys Subsystem.
  • Apply the patch b2fb0e13f5b4c8c2fb63dcfc2c37a067a0d6d20b.
  • Update the valkey-io valkey component.
  • Review the handleClientsBlockedOnKey function.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-82631.

URL Resource
https://github.com/user-attachments/files/30111628/PoC.zip
https://github.com/valkey-io/valkey/
https://github.com/valkey-io/valkey/commit/b2fb0e13f5b4c8c2fb63dcfc2c37a067a0d6d20b
https://github.com/valkey-io/valkey/issues/4198
https://github.com/valkey-io/valkey/pull/4212
https://vuldb.com/cve/CVE-2026-82631
https://vuldb.com/submit/893793
https://vuldb.com/vuln/397129
https://vuldb.com/vuln/397129/cti
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-82631 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-82631 weaknesses.

CAPEC-8: Buffer Overflow in an API Call Buffer Overflow in an API Call CAPEC-9: Buffer Overflow in Local Command-Line Utilities Buffer Overflow in Local Command-Line Utilities CAPEC-10: Buffer Overflow via Environment Variables Buffer Overflow via Environment Variables CAPEC-14: Client-side Injection-induced Buffer Overflow Client-side Injection-induced Buffer Overflow CAPEC-24: Filter Failure through Buffer Overflow Filter Failure through Buffer Overflow CAPEC-42: MIME Conversion MIME Conversion CAPEC-44: Overflow Binary Resource File Overflow Binary Resource File CAPEC-45: Buffer Overflow via Symbolic Links Buffer Overflow via Symbolic Links CAPEC-46: Overflow Variables and Tags Overflow Variables and Tags CAPEC-47: Buffer Overflow via Parameter Expansion Buffer Overflow via Parameter Expansion CAPEC-100: Overflow Buffers Overflow Buffers CAPEC-123: Buffer Manipulation Buffer Manipulation

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-82631 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-82631 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Aug. 31, 2026

    Action Type Old Value New Value
    Added Description A security flaw has been discovered in valkey-io valkey 9.1.0. The affected element is the function handleClientsBlockedOnKey of the file src/blocked.c of the component Blocked-on-keys Subsystem. The manipulation results in use after free. The attack may be performed from remote. A high complexity level is associated with this attack. The exploitability is described as difficult. The exploit has been released to the public and may be used for attacks. The patch is identified as b2fb0e13f5b4c8c2fb63dcfc2c37a067a0d6d20b. Applying a patch is advised to resolve this issue.
    Added CVSS V4.0 AV:N/AC:H/AT:N/PR:H/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L
    Added CVSS V2 (AV:N/AC:H/Au:M/C:N/I:N/A:P)
    Added CWE CWE-119
    Added CWE CWE-416
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/82xxx/CVE-2026-82631.json">CVE-2026-82631</a>
    Added Reference https://github.com/user-attachments/files/30111628/PoC.zip
    Added Reference https://github.com/valkey-io/valkey/
    Added Reference https://github.com/valkey-io/valkey/commit/b2fb0e13f5b4c8c2fb63dcfc2c37a067a0d6d20b
    Added Reference https://github.com/valkey-io/valkey/issues/4198
    Added Reference https://github.com/valkey-io/valkey/pull/4212
    Added Reference https://vuldb.com/cve/CVE-2026-82631
    Added Reference https://vuldb.com/submit/893793
    Added Reference https://vuldb.com/vuln/397129
    Added Reference https://vuldb.com/vuln/397129/cti
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 1.2
Attack Vector
Attack Complexity
Attack Requirements
Privileges Required
User Interaction
VS Confidentiality
VS Integrity
VS Availability
SS Confidentiality
SS Integrity
SS Availability
Base CVSS Score: 2.2
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact
Base CVSS Score: 1.7
Access Vector
Access Complexity
Authentication
Confidentiality Impact
Integrity Impact
Availability Impact