CVE-2025-55181 Denial of service in proxygen

Medium 5.3 Published 2 Dec 2025 Updated 3 Dec 2025

An attacker can cause a denial of service by sending oversized HTTP bodies, triggering an infinite loop and memory exhaustion in the Proxygen library.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2025-55181?

CVE-2025-55181 is a medium-severity denial of service vulnerability in Facebook proxygen, published on 2 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Sending an HTTP request/response body with greater than 2^31 bytes triggers an infinite loop in proxygen::coro::HTTPQuicCoroSession which blocks the backing event loop and unconditionally appends data to a std::vector per-loop iteration. This issue leads to unbounded memory growth and eventually causes the process to run out of memory.

Weakness: CWE-834

Which versions are affected by CVE-2025-55181?

It affects 1 product.

Products include Facebook Proxygen.

How do I fix CVE-2025-55181?

No fix has been published for CVE-2025-55181 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-2025-55181 being exploited?

There is no known exploitation of CVE-2025-55181 in the wild and no public exploit code.

Sources

Also known as GHSA-886p-82g3-p77g.