CVE-2026-21864
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedValkey-Bloom is a Rust based Valkey module which brings a Bloom Filter (Module) data type into the Valkey distributed key-value database. Prior to commit a68614b6e3845777d383b3a513cedcc08b3b7ccd, a specially crafted `RESTORE` command can cause Valkey to hit an assertion, causes the server to shutdown. Valkey modules are required to handle errors in RDB parsing by using `VALKEYMODULE_OPTIONS_HANDLE_IO_ERRORS` flag. If this flag is not set, errors encountered during parsing result in a system assertion which shuts down the system. Even though the Valkey-bloom module correctly handled the parsing, it did not originally set the flag. Commit a68614b6e3845777d383b3a513cedcc08b3b7ccd contains a patch. One may mitigate this defect by disabling the `RESTORE` command if it is unused by one's application.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysisThe application accepts input without confirming it is well-formed or within expected bounds, so malformed data can push the program into states its author never anticipated. Attackers probe these gaps to trigger crashes, bypass logic, or feed tainted values into more dangerous operations downstream. Remediating it well means validating and normalising every input at the boundary against a strict allow-list — not merely filtering known-bad values.
General guidance for the improper input validation class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 1.0.1CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped1.0.1
Valkey Bloom 1.0.1
- Identify the current Valkey Bloom version in use by checking the module info or Valkey `MODULE LIST` output
- Download Valkey Bloom version 1.0.1 or later from the official repository at https://github.com/valkey-io/valkey-bloom/releases
- Replace the existing Valkey Bloom module file (typically named `valkey-bloom.so` or similar) with the new version
- Restart Valkey to load the updated module, or use `MODULE LOAD`/`MODULE UNLOAD` to hot-reload if supported
- Verify the module loaded successfully with `MODULE LIST` and check for any errors
- As an additional precaution, consider disabling the `RESTORE` command in the Valkey configuration if not needed by setting `rename-command RESTORE ""` in valkey.conf
Generated from the published advisory — verify against the referenced sources before acting.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-21864 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-21864 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
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