CVE-2022-35921 is a low-severity (CVSS 3.5) Improper Privilege Management vulnerability in fof/byobu. A fix is available for fof/byobu — see the affected versions and patch details below.
User preference to prevent private discussions not respected in fof/byobu
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2022-35921.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2022-35921 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,333 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
fof/byobuReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
fof/byobu is a private discussions extension for Flarum forum. Affected versions were found to not respect private discussion disablement by users. Users of Byobu should update the extension to version 1.1.7, where this has been patched. Users of Byobu with Flarum 1.0 or 1.1 should upgrade to Flarum 1.2 or later, or evaluate the impact this issue has on your forum's users and choose to disable the extension if needed. There are no workarounds for this issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | fof/byobu | ≥ 0.3.0-beta.2&&< 1.1.7 | 1.1.7composer require fof/byobu:^1.1.7 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for fof/byobu, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update fof/byobu to 1.1.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-35921 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2022-35921 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2022-35921. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2022-35921 in your dependencies?
O3 Security finds CVE-2022-35921 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.