CVE-2026-82631: Buffer Overflow (CVSS 2.2)

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.

Is your site exposed to CVE-2026-82631?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

2.2

LOW

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

EPSS — Exploit Prediction

0.0036

Probability of exploitation

0.29%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-119 Buffer Overflow

CWE-416 Use After Free

References

Other References

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

Frequently Asked Questions

What is CVE-2026-82631? +

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. It has a CVSS v3.1 base score of 2.2 (LOW).

How severe is CVE-2026-82631? +

CVE-2026-82631 has a CVSS v3.1 score of 2.2 out of 10, rated LOW. This is a low-severity vulnerability with limited impact. The EPSS score is 0.0036, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-82631? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2024-11139

CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability exists that could allow local attackers to …

CVE-2025-1866

Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in warmcat libwebsockets allows Pointer Manipulation, potentially leading …

CVE-2025-2401

Buffer overflow vulnerability in Immunity Debugger affecting version 1.85, its exploitation could allow a local attacker to execute arbitrary code, …

CVE-2025-46333

z2d is a pure Zig 2D graphics library. Versions of z2d after `0.5.1` and up to and including `0.6.0`, when …

CVE-2025-6151

A vulnerability has been found in TP-Link TL-WR940N V4 and TL-WR841N V11. Affected by this issue is some unknown functionality …

CVE-2025-34096

A stack-based buffer overflow vulnerability exists in Easy File Sharing HTTP Server version 7.2. The flaw is triggered when a …

CVE-2026-82631