PatchTheCVECVE-2026-57858: Cal.com Cal.diy versions 2.1.1 through 6.2.0 contain a stored cross-site scripting vulnerability in the Bookin
CVE-2026-57858 is a high-severity flaw (CVSS 8.9) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Cal.com Cal.diy versions 2.1.1 through 6.2.0 contain a stored cross-site scripting vulnerability in the BookingPageTagManager component that allows authenticated event owners to inject arbitrary JavaScript by supplying a malicious analytics tracking ID without sanitization. Attackers can close the inline script string literal with a crafted payload that executes in the browser of every visitor to the affected public booking page, enabling session
Why this priority
- High severity
- CISA SSVC: public proof of concept
A fixed release or distro patch exists.
Risk facts
| CVSS score | 8.9 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | Required |
| EPSS exploit chance | 0.4% (top 70%) |
| CISA exploited list | No |
| Weakness | CWE-79 |
| Published | 2026-08-12 |
| Last modified | 2026-10-24 |
Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Exact fixes by distribution
Public exploits and detection
Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.
- GitHub PoC: zylideum/CVE-2026-57858 (0 stars)
- Write-up: ashtonr.com/blog/cve-2026-57858/
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-57858?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-57858 being exploited?
CVE-2026-57858 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-57858 affect?
CVE-2026-57858 affects affected software. Severity is high (CVSS 8.9). Cal.com Cal.diy versions 2.1.1 through 6.2.0 contain a stored cross-site scripting vulnerability in the BookingPageTagManager component that allows authenticated event owners to inject arbitrary JavaScript by supplying a malicious analytics
How urgent is CVE-2026-57858?
Priority 42/100. High severity; CISA SSVC: public proof of concept