CVE-2026-73249

calibre Content Server `/book-update-annotations` Missing Write Authorization Check Allows Unauthorized Annotation Modification

HIGH
7.5
CVSS Score
Published: August 11, 2026 at 09:58 PM UTC
Updated: October 24, 2026 at 03:10 PM UTC
1 product affected across 1 vendorCalibre

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Severity
HIGH7.5
Exploit prediction
EPSS 0.4%
SSVC
PoC

Description

calibre is an e-book manager. Prior to 9.12.0, the calibre Content Server endpoint POST /book-update-annotations/{library_id}/{book_id}/{fmt} in src/calibre/srv/books.py omits needs_db_write=True, causing Router.dispatch() to skip ctx.check_for_write_access() before update_annotations() passes attacker-controlled JSON to db.merge_annotations_for_book(), which allows a readonly user or an anonymous user on an unauthenticated deployment to persist unauthorized book annotation changes. This issue is fixed in version 9.12.0.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 9.12.0
Affected range stops below 9.12.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-862

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