# CVE-2026-48843: Server-side request forgery in Webmail

> Insufficient CSS sanitization in Roundcube Webmail allows attackers to trigger SSRF or disclose information via malicious stylesheet links in HTML emails.

- **Severity:** High 7.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 May 2026
- **Updated:** 26 May 2026
- **Also known as:** DEBIAN-CVE-2026-48843, GHSA-2hww-8583-w9wf, UBUNTU-CVE-2026-48843

## What is CVE-2026-48843?

CVE-2026-48843 is a high-severity server-side request forgery vulnerability in Roundcube Webmail, published on 25 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Roundcube Webmail 1.6.x between 1.6.14 and 1.6.16,and 1.7.x before 1.7.1 has Insufficient Cascading Style Sheets (CSS) sanitization in HTML e-mail messages may lead to SSRF or Information Disclosure, e.g., if stylesheet links point to local network hosts. The issue stems from an insufficient fix for CVE-2026-35540.

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

## Which versions are affected by CVE-2026-48843?


## How do I fix CVE-2026-48843?

Upgrade to a fixed version.

## Is CVE-2026-48843 being exploited?

There is no known exploitation of CVE-2026-48843 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-48843 and fix it if it is affected.

What it is: CVE-2026-48843 is a high-severity server-side request forgery vulnerability in Roundcube Webmail, published on 25 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-48843 in the wild and no public exploit code.

Affected product: Roundcube Webmail. 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-2026-48843/ (Markdown: https://insights.sbomify.com/CVE-2026-48843/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-48843
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-48843
- OSV: https://osv.dev/vulnerability/CVE-2026-48843

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-48843/
Summaries are generated and may contain mistakes; the official description above is the record.