What is CVE-2026-44909?

CVE-2026-44909 is a high-severity vulnerability in Facebook Proxygen, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-07-23.

How severe is CVE-2026-44909?

High severity. CVSS v3 base score is 7.5 out of 10.

Resource exhaustion in Facebook Proxygen

CVE-2026-44909

Proxygen lacked a generalized slow-consumer detection mechanism in its core HTTP session layer. A remote, unauthenticated attacker could exploit HTTP/2 flow-control by setting SETTINGS_INITIAL_WINDOW_SIZE to 0 or withholding WINDOW_UPDATE…

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Facebook Proxygen — versions v2017.01.16.00

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

cve-assign@fb.com (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2026-44909?: CVE-2026-44909 is a high-severity vulnerability in Facebook Proxygen, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-07-23.
How severe is CVE-2026-44909?: High severity. CVSS v3 base score is 7.5 out of 10.