OSV-2025-989 Bad-cast to UT_hash_bucket' (aka 'struct UT_hash_bucket')password_file__cleanup
A bad-cast vulnerability in the Mosquitto MQTT broker's password file cleanup routine can cause a crash, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is OSV-2025-989?
OSV-2025-989 is a memory corruption vulnerability in mosquitto, published on 17 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=468922225
Crash type: Bad-cast
Crash state:
Bad-cast to UT_hash_bucket' (aka 'struct UT_hash_bucket')password_file__cleanup
mosquitto_security_cleanup_default
broker_fuzz_password_file.cpp
Which versions are affected by OSV-2025-989?
1 open source package ship an affected version, including mosquitto.
| Package | Affected | Fixed in |
|---|---|---|
mosquitto OSS-Fuzz | All versions | None |
How do I fix OSV-2025-989?
No fix has been published for OSV-2025-989 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is OSV-2025-989 being exploited?
There is no known exploitation of OSV-2025-989 in the wild and no public exploit code.