7.5
HIGH CVSS 3.1
CVE-2026-73249
calibre Content Server `/book-update-annotations` Missing Write Authorization Check Allows Unauthorized Annotation Modification
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.

INFO

Published Date :

Aug. 11, 2026, 10:19 p.m.

Last Modified :

Aug. 11, 2026, 10:19 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-73249 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH [email protected]
CVSS 3.1 HIGH MITRE-CVE
Solution
Update calibre to version 9.12.0 or later to fix unauthorized annotation changes.
  • Update calibre to version 9.12.0 or later.
  • Verify Content Server access controls.
  • Apply updates promptly to prevent unauthorized access.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-73249.

URL Resource
https://github.com/kovidgoyal/calibre/commit/71295e8b62801e1ccecaa4fac47e6942f11cfe1e
https://github.com/kovidgoyal/calibre/releases/tag/v9.12.0
https://github.com/kovidgoyal/calibre/security/advisories/GHSA-5x64-w63v-x2g6
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-73249 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-73249 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-73249 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-73249 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Aug. 11, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'kovidgoyal', 'product': 'calibre', 'versions': [{'status': 'affected', 'version': '< 9.12.0'}]}]
    Added 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.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
    Added CWE CWE-862
    Added Reference https://github.com/kovidgoyal/calibre/commit/71295e8b62801e1ccecaa4fac47e6942f11cfe1e
    Added Reference https://github.com/kovidgoyal/calibre/releases/tag/v9.12.0
    Added Reference https://github.com/kovidgoyal/calibre/security/advisories/GHSA-5x64-w63v-x2g6
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.