CVE-2026-110103 bbs-go through 4.4.6 Stored XSS via Image Upload Content-Type
Authenticated users can upload malicious HTML or SVG files via Content-Type spoofing, leading to stored XSS and potential administrator account takeover.
- 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
- None listed
What is CVE-2026-110103?
CVE-2026-110103 is a medium-severity cross-site scripting vulnerability in mlogclub bbs-go, 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
bbs-go through 4.4.6 contains a stored cross-site scripting vulnerability that allows authenticated users to upload HTML or SVG files by spoofing the multipart Content-Type in POST /api/upload. Attackers can upload script-bearing documents served inline from /res and send their URLs to administrators, executing script on the forum's origin.
Weakness: CWE-79
Which versions are affected by CVE-2026-110103?
How do I fix CVE-2026-110103?
No fix has been published for CVE-2026-110103 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-110103 being exploited?
There is no known exploitation of CVE-2026-110103 in the wild and no public exploit code.
Sources
Also known as GHSA-rm26-pxjp-76q3.