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Not in CISA KEV
HIGH severity

CVE-2022-0877 ssddanbrown/bookstack

HIGHFix: bookstackapp/bookstack@856fca8

CVE-2022-0877 is a high-severity (CVSS 7.6) Cross-site Scripting (XSS) vulnerability in ssddanbrown/bookstack. 1 public exploit reference exists, so weaponization risk is real. A fix is available for ssddanbrown/bookstack — see the affected versions and patch details below.

Cross-site Scripting (XSS) - Stored in bookstackapp/bookstack

Also known asGHSA-5rcc-6cmj-7728
Published
Mar 8, 2022
Updated
Aug 12, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
1 known
Exploitation data as of Sep 21, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
0.8%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs54th percentile — riskier than 54% of all scored CVEsHighest risk

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-2022-0877 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 377,636 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

1 pkg affected
🐘ssddanbrown/bookstack

Real-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

Iframe tags don't have a sandbox attribute, this makes an attacker able to execute malicious javascript via an iframe and perform phishing attacks. The sandbox attribute will block script execution and prevents the content to navigate its top-level browsing context which will stop this type of attack.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐘Packagistssddanbrown/bookstackall versions22.02.3composer require ssddanbrown/bookstack:^22.02.3
Exploits & PoCs
1

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ssddanbrown/bookstack, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update ssddanbrown/bookstack to 22.02.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-0877 is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2022-0877 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2022-0877. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Iframe tags don't have a sandbox attribute, this makes an attacker able to execute malicious javascript via an iframe and perform phishing attacks. The sandbox attribute will block script execution and prevents the content to navigate its top-level browsing context which will stop this type of attack.
O3 Security · Impact-Aware SCA

Is CVE-2022-0877 in your dependencies?

O3 Security finds CVE-2022-0877 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

CVE-2022-0877: ssddanbrown/bookstack | O3 Security