CVE-2026-73248
Arbitrary code execution in calibre via crafted ebook templates (pre-9.12.0).
Is CVE-2026-73248 being exploited?
Not confirmed. CVE-2026-73248 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 0.21% probability of exploitation in the next 30 days.
How severe is CVE-2026-73248?
CVE-2026-73248 is rated High. 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-2026-73248?
Yes. A fix has been recorded for CVE-2026-73248. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-73248 affect?
CVE-2026-73248 affects calibre < 9.12.0 (Windows/macOS/Linux), calibre ebook viewer/importer. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-73248?
Update to calibre 9.12.0+ and avoid untrusted ebook files
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Arbitrary Python code execution when opening/importing a crafted EPUB/OPF/PDF, enabling full system compromise.
Patch when possible
- affected< 9.12.0
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.