CVE-2026-22659
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 · uneditedFlaskBB through 2.2.0, fixed in commit acc88cf, contains an authorization bypass vulnerability that allows authenticated moderators to perform unauthorized actions on topics in forums they do not control by submitting crafted topic ID lists. Attackers can include a low-ID topic from a permitted forum as an anchor in a batch request, causing the permission check applied only to the first result to pass, and then execute lock, unlock, delete, or hide actions against topics in unmoderated forums.
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 analysis · high confidenceFlaskBB through 2.2.0 has an authorization bypass where batch moderator actions (lock, unlock, delete, hide) only validate permissions on the first topic ID in a request. Attackers exploit this by including a low-ID topic from a permitted forum as an anchor, bypassing permission checks for subsequent topics in unmoderated forums.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify FlaskBB installation and versionLocate the FlaskBB installation and check the version file or package metadata. Common locations include the application root directory containing a version file or setup.py/pyproject.toml with version information. Compare the installed version to the affected range (through 2.2.0).Affected if The installed version is 2.2.0 or earlier (any version up to and including 2.2.0).
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Verify batch moderation feature existsInspect the FlaskBB source code for batch moderation functionality. Look for endpoints handling multiple topic IDs in a single request, typically in moderation-related routes or views that accept topic ID lists for bulk operations.Affected if The batch moderation endpoints accepting topic ID lists are present in the codebase.
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Locate the vulnerable permission check logicExamine the batch moderation view functions in the code. Search for the permission validation logic that processes submitted topic ID lists. Look for code that only retrieves or validates the first item from the submitted list.Affected if The code shows permission validation occurs only on the first topic ID from the submitted list, with subsequent IDs processed without individual authorization checks.
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Review moderator role configurationCheck if any user accounts are assigned moderator privileges. Look at the user roles and permissions configuration in the FlaskBB database or configuration files to identify authenticated users with moderator-level access.Affected if Moderator accounts exist that could leverage the batch moderation feature to exploit the authorization bypass.
You are affected if running FlaskBB version 2.2.0 or earlier with the batch moderation feature accessible to moderators, as the code only validates authorization on the first topic ID in a batch request.
Generated from the published advisory. Verify against your own configuration.
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 · scopedApply the fix from commit acc88cf which ensures permission checks are applied to ALL topics in batch operations, not just the first result.
FlaskBB 2.2.1 or later (or the commit acc88cf)
- Check the current FlaskBB version by examining the installation or version file
- Upgrade FlaskBB to the latest stable release that includes the fix (version 2.2.1 or later)
- If a newer release is not available, manually apply the fix by cherry-picking or applying commit acc88cfedd011124395e0101cb27432a47f712be from https://github.com/flaskbb/flaskbb/commit/acc88cfedd011124395e0101cb27432a47f712be
- After applying the patch, verify the fix by testing moderator actions on cross-forum topic IDs to ensure authorization is properly enforced
- Restart the FlaskBB application to ensure all changes take effect
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-22659 — 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-2026-22659 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
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data