CVE-2025-35435 CISA Thorium download stream divide by zero
A remote authenticated attacker can crash the CISA Thorium service by providing a zero stream split size, causing a divide-by-zero error.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-35435?
CVE-2025-35435 is a medium-severity denial of service vulnerability in CISA Thorium, published on 17 Sep 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
CISA Thorium accepts a stream split size of zero then divides by this value. A remote, authenticated attacker could cause the service to crash. Fixed in commit 89101a6.
Weakness: CWE-369
Which versions are affected by CVE-2025-35435?
It affects 1 product.
Products include Cisa Thorium.
How do I fix CVE-2025-35435?
No fix has been published for CVE-2025-35435 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-35435 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-35435 exists.
Other vulnerabilities in CISA Thorium
- CVE-2025-35432 CISA Thorium does not rate limit account verification email messages
- CVE-2025-35436 CISA Thorium account verification email error handling
- CVE-2025-35430 CISA Thorium insecure downloaded file path validation
- CVE-2025-35431 CISA Thorium LDAP injection
- CVE-2025-35433 CISA Thorium does not properly invalidate previously used tokens
Sources
Also known as GHSA-w2x7-fc9j-4572.