CVE-2026-54527
Stored XSS in JupyterLab Git via crafted filename in rename diff.
Is CVE-2026-54527 being exploited?
Not confirmed. CVE-2026-54527 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.53% probability of exploitation in the next 30 days.
How severe is CVE-2026-54527?
CVE-2026-54527 is rated Critical with a CVSS score of 9.3. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-54527?
Yes. A fix has been recorded for CVE-2026-54527. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-54527 affect?
CVE-2026-54527 affects JupyterLab Git extension >=0.30.0b3 and <0.54.0. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-54527?
Upgrade JupyterLab Git to 0.54.0+ and avoid opening untrusted repositories.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Stored XSS: attacker-supplied filename executes JS in a viewer's browser, enabling session theft, CSRF, or arbitrary browser-side actions.
Immediate action required
- affected>= 0.30.0b3 and < 0.54.0
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.