CVE-2026-25635 calibre has a Path Traversal Leading to Arbitrary File Write and Potential Code Execution
Attackers can exploit a path traversal in the CHM reader to write arbitrary files, potentially achieving remote code execution on Windows systems.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-25635?
CVE-2026-25635 is a high-severity path traversal vulnerability in kovidgoyal calibre, published on 6 Feb 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
calibre is an e-book manager. Prior to 9.2.0, Calibre's CHM reader contains a path traversal vulnerability that allows arbitrary file writes anywhere the user has write permissions. On Windows (haven't tested on other OS's), this can lead to Remote Code Execution by writing a payload to the Startup folder, which executes on next login. This vulnerability is fixed in 9.2.0.
Weakness: CWE-22
Which versions are affected by CVE-2026-25635?
It affects 1 product.
Products include Calibre-Ebook Calibre.
How do I fix CVE-2026-25635?
Upgrade to a fixed version.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-25635 being exploited?
There is no known exploitation of CVE-2026-25635 in the wild and no public exploit code.
Other vulnerabilities in kovidgoyal calibre
- CVE-2011-4124 Command injection in Calibre
- CVE-2011-4125 Privilege escalation in Calibre
- CVE-2026-26064 calibre: Path Traversal Vulnerability Enables Arbitrary File Write and Remote Code Execution
- CVE-2026-26065 calibre: Path Traversal can Lead to Arbitrary File Write and Potential Code Execution
- CVE-2026-33206 calibre has a path traversal vulnerability
Sources
Also known as DEBIAN-CVE-2026-25635, GHSA-32vh-whvh-9fxr, UBUNTU-CVE-2026-25635.