# CVE-2026-75838: DOMPurify before 3.4.13 Cross-Site Scripting via IN_PLACE hook

> Attackers can execute arbitrary JavaScript via event handlers in detached subtrees bypassing DOMPurify's IN_PLACE sanitization hooks.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 18 Aug 2026
- **Updated:** 18 Aug 2026
- **Also known as:** CLEANSTART-2026-NP83776, CLSA-2026-1789146579, CLSA-2026-1789146735, CLSA-2026-1789155227, CLSA-2026-1792497323, CLSA-2026-1792509522, DEBIAN-CVE-2026-75838, ECHO-4f41-1efa-827a, GHSA-55q2-fjhq-7xh7, GHSA-748c-f84h-hp2v, MINI-4824-prx6-c85q, MINI-4j39-323p-qq66, MINI-5wvj-93g6-xjpx, MINI-84xc-8f6f-5pmq, MINI-8mgx-6pgq-pp8g, MINI-8qq6-w79q-gvmw, MINI-8rvw-78hr-wpxv, MINI-9gxr-jqpv-gw9x, MINI-f842-xv8j-h7c6, MINI-fwp9-c6c5-3hr8, MINI-jm8r-w6r6-c2c9, MINI-mrwc-9rp6-2w4j, MINI-p345-r397-2j6w, MINI-qfq9-g42f-35xm, MINI-r775-rcch-57vj, MINI-rwc2-24wp-jh9m, MINI-vp67-q78f-q533, MINI-vrp8-v8qc-3qv4, MINI-x92f-c9wm-r438, RHSA-2026:70917, RHSA-2026:70994, UBUNTU-CVE-2026-75838

## What is CVE-2026-75838?

CVE-2026-75838 is a medium-severity cross-site scripting vulnerability in cure53 DOMPurify, published on 18 Aug 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

DOMPurify before 3.4.13 contains a cross-site scripting vulnerability in IN_PLACE sanitization where element-removal hooks fail to neutralize detached subtrees. Attackers can supply HTML with event handlers on descendant elements that execute after sanitization completes, even though the returned root appears clean.

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

## Which versions are affected by CVE-2026-75838?

2 open source packages ship an affected version, including dompurify.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `dompurify` | npm | All versions | 3.4.13 |
| `dompurify` | npm | All versions | 3.4.13 |
| `grafana12.4` | Red Hat:hummingbird:1 | All versions | 0:12.4.10-0.7.hum1 |
| `grafana13.2` | Red Hat:hummingbird:1 | All versions | 0:13.2.1-0.6.hum1 |

## How do I fix CVE-2026-75838?

Upgrade dompurify to 3.4.13 or later.

## Is CVE-2026-75838 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-75838 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-75838 and fix it if it is affected.

What it is: CVE-2026-75838 is a medium-severity cross-site scripting vulnerability in cure53 DOMPurify, published on 18 Aug 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-75838 exists.

Affected packages and fixed versions:
- dompurify (npm): affected all versions; fixed in 3.4.13
- dompurify (npm): affected all versions; fixed in 3.4.13

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-2026-75838/ (Markdown: https://insights.sbomify.com/CVE-2026-75838/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-75838
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-75838
- OSV: https://osv.dev/vulnerability/CVE-2026-75838

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-75838/
Summaries are generated and may contain mistakes; the official description above is the record.