What is CVE-2025-55181?

CVE-2025-55181 is a medium-severity vulnerability in Facebook Proxygen, classified under Excessive Iteration. CVSS score: 5.3/10. Published 2025-12-02.

How severe is CVE-2025-55181?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in Facebook Proxygen

CVE-2025-55181

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. T…

EPSS: 0.003 (16.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

Affected products

Facebook Proxygen — versions v2025.08.25.00

Weakness classification (CWE)

CWE-834 — Excessive Iteration

References

cve-assign@fb.com (x_refsource_CONFIRM, Vendor Advisory)
cve-assign@fb.com (x_refsource_CONFIRM, Patch)

Frequently asked questions

What is CVE-2025-55181?: CVE-2025-55181 is a medium-severity vulnerability in Facebook Proxygen, classified under Excessive Iteration. CVSS score: 5.3/10. Published 2025-12-02.
How severe is CVE-2025-55181?: Medium severity. CVSS v3 base score is 5.3 out of 10.