# CVE-2026-8656: Cross-site scripting in jsondiffpatch

> An attacker can execute arbitrary scripts in a victim's browser by exploiting improper sanitization in the jsondiffpatch library's annotated formatter.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N/E:P`)
- **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:** 16 May 2026
- **Updated:** 18 May 2026
- **Also known as:** GHSA-2f3m-j83v-344c

## What is CVE-2026-8656?

CVE-2026-8656 is a medium-severity cross-site scripting vulnerability in jsondiffpatch, published on 16 May 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

Versions of the package jsondiffpatch before 0.7.6 are vulnerable to Cross-site Scripting (XSS) via the annotated formatter due to improper sanitization of JSON values and property names. If an application compares untrusted JSON/object data and renders annotated formatter output in the DOM, attacker-controlled HTML can be interpreted by the browser, resulting in XSS.

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

## Which versions are affected by CVE-2026-8656?


## How do I fix CVE-2026-8656?

No fix has been published for CVE-2026-8656 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-8656 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-8656 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-8656 and fix it if it is affected.

What it is: CVE-2026-8656 is a medium-severity cross-site scripting vulnerability in jsondiffpatch, published on 16 May 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: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-8656 exists.

Affected product: jsondiffpatch. 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-2026-8656/ (Markdown: https://insights.sbomify.com/CVE-2026-8656/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-8656
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-8656
- OSV: https://osv.dev/vulnerability/CVE-2026-8656

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-8656/
Summaries are generated and may contain mistakes; the official description above is the record.