# CVE-2026-33205: calibre has Server-Side Request Forgery in ebook viewer backend

> An attacker can exploit a Server-Side Request Forgery flaw in calibre's ebook viewer to perform blind GET requests and exfiltrate data from the sandbox.

- **Severity:** Medium 4.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **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:** 27 Mar 2026
- **Updated:** 27 Mar 2026
- **Also known as:** DEBIAN-CVE-2026-33205, GHSA-4926-v9px-wv7v, UBUNTU-CVE-2026-33205

## What is CVE-2026-33205?

CVE-2026-33205 is a medium-severity server-side request forgery vulnerability in kovidgoyal calibre, published on 27 Mar 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 a cross-platform e-book manager for viewing, converting, editing, and cataloging e-books. Prior to version 9.6.0, a Server-Side Request Forgery vulnerability in the background-image endpoint of calibre e-book reader's web view allows an attacker to perform blind GET requests to arbitrary URLs and exfiltrate information out from the ebook sandbox. Version 9.6.0 patches the issue.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-33205?

It affects 1 product.


Products: Calibre-Ebook Calibre.

## How do I fix CVE-2026-33205?

Upgrade to a fixed version.

## Is CVE-2026-33205 being exploited?

There is no known exploitation of CVE-2026-33205 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-2026-33205 and fix it if it is affected.

What it is: CVE-2026-33205 is a medium-severity server-side request forgery vulnerability in kovidgoyal calibre, published on 27 Mar 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-2026-33205 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-2026-33205/ (Markdown: https://insights.sbomify.com/CVE-2026-33205/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33205
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33205
- OSV: https://osv.dev/vulnerability/CVE-2026-33205

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33205/
Summaries are generated and may contain mistakes; the official description above is the record.