CVE-2026-86227: Buffer Overflow (CVSS 3.1)

Description

A weakness has been identified in valkey-io valkey up to 9.0.5/9.1.1. This affects the function kvstoreGetHashtable of the file src/kvstore.c. This manipulation of the argument didx causes out-of-bounds read. It is possible to initiate the attack remotely. The attack is considered to have high complexity. It is indicated that the exploitability is difficult. The exploit has been made available to the public and could be used for attacks. Patch name: 4691888e7fab3df128f0bde5750c9fde2ae552fa. To fix this issue, it is recommended to deploy a patch. Exploitation requires cluster mode plus attacker-controlled dump.rdb at startup (data-dir write access, replication feed, or a stored crafted RDB) - an attacker-position DoS at boot, not network pre-auth. The issue report was closed stating it "is worth fixing for the sake of memory safety… but I don't think it meets our bar for a security disclosure."

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CVSS v3.1 Score

3.1

LOW

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

EPSS — Exploit Prediction

0.0032

Probability of exploitation

0.25%

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-125 Out-of-bounds Read

References

Other References

https://github.com/user-attachments/files/30195539/RDB.zip https://github.com/valkey-io/valkey/ https://github.com/valkey-io/valkey/commit/4691888e7fab3df128f0bde5750c9fde2ae552fa https://github.com/valkey-io/valkey/issues/4222 https://github.com/valkey-io/valkey/pull/4229 https://vuldb.com/cve/CVE-2026-86227 https://vuldb.com/submit/897659 https://vuldb.com/vuln/399380 https://vuldb.com/vuln/399380/cti

Frequently Asked Questions

What is CVE-2026-86227? +

A weakness has been identified in valkey-io valkey up to 9.0.5/9.1.1. This affects the function kvstoreGetHashtable of the file src/kvstore.c. This manipulation of the argument didx causes out-of-bounds read. It is possible to initiate the attack remotely. The attack is considered to have high complexity. It is indicated that the exploitability is difficult. The exploit has been made available to the public and could be used for attacks. Patch name: 4691888e7fab3df128f0bde5750c9fde2ae552fa. To fix this issue, it is recommended to deploy a patch. Exploitation requires cluster mode plus attacker-controlled dump.rdb at startup (data-dir write access, replication feed, or a stored crafted RDB) - an attacker-position DoS at boot, not network pre-auth. The issue report was closed stating it "is worth fixing for the sake of memory safety… but I don't think it meets our bar for a security disclosure." It has a CVSS v3.1 base score of 3.1 (LOW).

How severe is CVE-2026-86227? +

CVE-2026-86227 has a CVSS v3.1 score of 3.1 out of 10, rated LOW. This is a low-severity vulnerability with limited impact. The EPSS score is 0.0032, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-86227? +

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.

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