valkey: Use After Free
CVE-2026-63639 is a high-severity use after free vulnerability in valkey from Valkey-io, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected valkey versions: < 7.2.14; >= 8.0.0, < 8.0.10; >= 8.1.0, < 8.1.9, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.89% chance of exploitation within 30 days, higher than 60% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of valkey you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Valkey-io | valkey | < 7.2.14; >= 8.0.0, < 8.0.10; >= 8.1.0, < 8.1.9; >= 9.0.0, < 9.0.5; >= 9.1.0, < 9.1.1 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (github.com).
Official 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- github.com/valkey-io/valkey/commit/06bc7768fe609f2054e69ccedefe7628f5675da9
- github.com/valkey-io/valkey/commit/509cb3c74e8cbc9c0498ebe8b6c93dcd605e7271
- github.com/valkey-io/valkey/commit/98465eaffe3f95524a5046318bfbc4bdb9798291
- github.com/valkey-io/valkey/commit/e95911d4d65be8789fa3705f44d7ed1e65378445
- github.com/valkey-io/valkey/commit/f8d2027e8d4df790ac04974bf606408c8ea62778
- github.com/valkey-io/valkey/pull/4073
- github.com/valkey-io/valkey/releases/tag/7.2.14
- github.com/valkey-io/valkey/releases/tag/8.0.10
- github.com/valkey-io/valkey/releases/tag/8.1.9
- github.com/valkey-io/valkey/releases/tag/9.0.5
- github.com/valkey-io/valkey/releases/tag/9.1.1
Other vulnerabilities in valkey
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.1 High severity
Recent Use After Free vulnerabilities
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
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