CVE-2023-33187 is a medium-severity (CVSS 5.4) CWE-319 vulnerability in highlight.run. A fix is available for highlight.run — see the affected versions and patch details below.
html inputs of type password recorded in plaintext when converted to text inputs
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-2023-33187.
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-2023-33187 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 378,156 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
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
highlight.runnpmDescription
Impact
Highlight may record passwords on customer deployments when a password html input is switched to type="text" via a javascript "Show Password" button. This differs from the expected behavior which always obfuscates type="password" inputs. A customer may assume that switching to type="text" would also not record this input; hence, they would not add additional highlight-mask css-class obfuscation to this part of the DOM, resulting in unintentional recording of a password value when a Show Password button is used.
Patches
[email protected] resolves the issue via https://github.com/rrweb-io/rrweb/pull/1184
This patch tracks changes to the type attribute of an input to ensure an input that used to be a type="password" continues to be obfuscated.
Workarounds
We have deployed a change to our data ingest to obfuscate passwords server side from older clients. This means that upgrading to the latest version of highlight.run is not necessary but recommended to prevent potential network transfer of recorded password data to our backend.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | highlight.run | all versions | 6.0.0npm install highlight.run@6.0.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for highlight.run, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update highlight.run to 6.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-33187 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-2023-33187 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-33187. 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-2023-33187 in your dependencies?
O3 Security finds CVE-2023-33187 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.