# CVE-2026-55562: Cronicle: Stored XSS in admin Activity Log via account full_name field

> An attacker can inject malicious scripts into the admin Activity Log via the user full_name field, leading to administrator account takeover and command execution.

- **Severity:** Critical 9.0 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H`)
- **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:** No
- **Published:** 13 Oct 2026
- **Updated:** 16 Oct 2026
- **Also known as:** GHSA-vh39-3pcm-2j63

## What is CVE-2026-55562?

CVE-2026-55562 is a critical cross-site scripting vulnerability in jhuckaby Cronicle, published on 13 Oct 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

Cronicle is a multi-server task scheduler and runner, with a web based front-end UI. Prior to 0.9.119, the administrator Activity Log in htdocs/js/pages/admin/Activity.js concatenates the attacker-controlled item.user.full_name value into HTML without applying encode_entities and inserts the result through this.div.html. The bundled pixl-server-user input filter can be bypassed by a tag containing a line break because its regular expression does not match newlines. An authenticated non-administrator can update the attacker's own name through /api/user/update using a valid session and current password; when free_accounts is enabled, an anonymous attacker can instead plant the name during self-registration. The stored name executes script in an administrator's session when the Activity Log is opened, enabling administrator takeover and subsequent command execution through privileged Cronicle features. This issue is fixed in version 0.9.119.

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

## Which versions are affected by CVE-2026-55562?


## How do I fix CVE-2026-55562?

No fix has been published for CVE-2026-55562 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-55562 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55562 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55562 and fix it if it is affected.

What it is: CVE-2026-55562 is a critical cross-site scripting vulnerability in jhuckaby Cronicle, published on 13 Oct 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-2026-55562 exists.

Affected product: jhuckaby Cronicle. 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-2026-55562/ (Markdown: https://insights.sbomify.com/CVE-2026-55562/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55562
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55562
- OSV: https://osv.dev/vulnerability/CVE-2026-55562

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-55562/
Summaries are generated and may contain mistakes; the official description above is the record.