# CVE-2026-1439: Reflected Cross-Site Scripting (XSS) vulnerability in Graylog Web Interface

> Attackers can execute arbitrary JavaScript in victims' browsers via crafted URLs in the Graylog Web Interface, potentially compromising user sessions.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 18 Feb 2026
- **Updated:** 18 Feb 2026
- **Also known as:** GHSA-49xw-73mm-8fw9

## What is CVE-2026-1439?

CVE-2026-1439 is a medium-severity cross-site scripting vulnerability in Graylog Web Interface, published on 18 Feb 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Reflected Cross-Site Scripting (XSS) vulnerability in the Graylog Web Interface console, version 2.2.3, caused by a lack of proper sanitization and escaping in HTML output. Several endpoints include segments of the URL directly in the response without applying output encoding, allowing an attacker to inject and execute arbitrary JavaScript code when a user visits a specially crafted URL. Exploitation of this vulnerability may allow script execution in the victim's browser and limited manipulation of the affected user's session context, through the  '/

alerts

/' endpoint.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-1439?

It affects 1 product.


Products: Graylog Graylog.

## How do I fix CVE-2026-1439?

No fix has been published for CVE-2026-1439 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-1439 being exploited?

There is no known exploitation of CVE-2026-1439 in the wild and no public exploit code.

## Other vulnerabilities in Graylog Web Interface

- [CVE-2021-37759](https://insights.sbomify.com/CVE-2021-37759/): Information disclosure in n/a (critical 9.8)
- [CVE-2021-37760](https://insights.sbomify.com/CVE-2021-37760/): Information disclosure in n/a (critical 9.8)
- [CVE-2026-1435](https://insights.sbomify.com/CVE-2026-1435/): Incorrect management of session invalidation vulnerability in Graylog Web Interface (critical 9.3)
- [CVE-2025-53106](https://insights.sbomify.com/CVE-2025-53106/): Graylog vulnerable to privilege escalation through API tokens (high 8.8)
- [CVE-2024-24824](https://insights.sbomify.com/CVE-2024-24824/): graylog2-server vulnerable to instantiation of arbitrary classes triggered by API request (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-1439 and fix it if it is affected.

What it is: CVE-2026-1439 is a medium-severity cross-site scripting vulnerability in Graylog Web Interface, published on 18 Feb 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-1439 in the wild and no public exploit code.

Affected product: Graylog Web Interface. 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-2026-1439/ (Markdown: https://insights.sbomify.com/CVE-2026-1439/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-1439
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-1439
- OSV: https://osv.dev/vulnerability/CVE-2026-1439

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-1439/
Summaries are generated and may contain mistakes; the official description above is the record.