CVE-2026-63639

HIGH

8.8

CVSS v3

Description

Valkey is a distributed key-value database. Prior to 7.2.14, 8.0.10, 8.1.9, 9.0.5, and 9.1.1, Valkey's RESTORE command accepts a malformed RDB stream payload that assigns one Pending Entry List NACK to multiple consumers during stream consumer-group deserialization, causing a use-after-free when one consumer is deleted while another still references the shared NACK and potentially allowing remote code execution. This issue is fixed in versions 7.2.14, 8.0.10, 8.1.9, 9.0.5, and 9.1.1.

CWE-416Use After Free

How to fix

Remediation Available

valkeyDebian

Fixed in:9.1.1-1CVE-2026-63639

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Exploit Intelligence

0.89%probability of exploitation in 30 days

57thpercentile

Moderate risk: more likely to be exploited than 57% of all known CVEs.

References

Other references12

Related Vulnerabilities

Other CWE-416 (Use After Free) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2019-0708	Critical	9.8	100%	KEV + Ransom	-
CVE-2021-31166	Critical	9.8	100%	KEV	Fix
CVE-2015-5119	Critical	9.8	99%	KEV	-
CVE-2010-3962	High	8.1	97%	KEV	-
CVE-2015-0313	Critical	9.8	96%	KEV	Fix
CVE-2021-34833	High	7.8	96%	-	-

Common questions

How do I fix CVE-2026-63639?

Upgrade valkey on debian unstable to 9.1.1-1 or later.

Is CVE-2026-63639 being actively exploited?

Not that we know of. CVE-2026-63639 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.89% is the estimated probability that it will be exploited in the next 30 days. That is higher than 57% of all scored CVEs.

How severe is CVE-2026-63639?

CVE-2026-63639 has a CVSS v3 base score of 8.8, rated important. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-63639 affect?

Published advisories record a fix for valkey (Debian). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-08-20.