# CVE-2026-25636: calibre has a Path Traversal Leading to Arbitrary File Corruption and Code Execution

> A malicious EPUB file can trigger path traversal in Calibre, allowing arbitrary file corruption and potential code execution.

- **Severity:** High 8.2 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:H`)
- **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:** Yes
- **Published:** 6 Feb 2026
- **Updated:** 11 Feb 2026
- **Also known as:** DEBIAN-CVE-2026-25636, GHSA-8r26-m7j5-hm29, UBUNTU-CVE-2026-25636

## What is CVE-2026-25636?

CVE-2026-25636 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. In 9.1.0 and earlier, a path traversal vulnerability in Calibre's EPUB conversion allows a malicious EPUB file to corrupt arbitrary existing files writable by the Calibre process. During conversion, Calibre resolves CipherReference URI from META-INF/encryption.xml to an absolute filesystem path and opens it in read-write mode, even when it points outside the conversion extraction directory. This vulnerability is fixed in 9.2.0.

Weakness: CWE-94 (Improper Control of Generation of Code), CWE-73 (External Control of File Name or Path), CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-25636?

It affects 1 product.


Products: Calibre-Ebook Calibre.

## How do I fix CVE-2026-25636?

Upgrade to a fixed version.

## Is CVE-2026-25636 being exploited?

There is no known exploitation of CVE-2026-25636 in the wild and no public exploit code.

## Other vulnerabilities in kovidgoyal calibre

- [CVE-2011-4124](https://insights.sbomify.com/CVE-2011-4124/): Command injection in Calibre (critical 9.8)
- [CVE-2011-4125](https://insights.sbomify.com/CVE-2011-4125/): Privilege escalation in Calibre (critical 9.8)
- [CVE-2026-26064](https://insights.sbomify.com/CVE-2026-26064/): calibre: Path Traversal Vulnerability Enables Arbitrary File Write and Remote Code Execution (critical 9.3)
- [CVE-2026-26065](https://insights.sbomify.com/CVE-2026-26065/): calibre: Path Traversal can Lead to Arbitrary File Write and Potential Code Execution (critical 9.3)
- [CVE-2026-25635](https://insights.sbomify.com/CVE-2026-25635/): calibre has a Path Traversal Leading to Arbitrary File Write and Potential Code Execution (high 8.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-25636 and fix it if it is affected.

What it is: CVE-2026-25636 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.
Exploitation: There is no known exploitation of CVE-2026-25636 in the wild and no public exploit code.

Affected product: kovidgoyal calibre. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-25636/ (Markdown: https://insights.sbomify.com/CVE-2026-25636/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-25636
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-25636
- OSV: https://osv.dev/vulnerability/CVE-2026-25636

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-25636/
Summaries are generated and may contain mistakes; the official description above is the record.