CVE-2026-44909 Details
Description
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 frames, causing the server to buffer complete response bodies in memory indefinitely for stalled streams. By opening many simultaneous streams requesting large resources while preventing the server from transmitting responses, an attacker could induce unbounded memory growth leading to service degradation, resource exhaustion, or denial of service. Versions v2017.01.16.00 through v2026.07.20.00 are affected.
A denial-of-service vulnerability has been identified in Proxygen versions v2017.01.16.00 prior to v2026.07.20.00. The issue arises from the lack of a generalized slow-consumer detection mechanism in the core HTTP session layer, which allows remote, unauthenticated attackers to exploit HTTP/2 flow control. By setting the initial window size to zero or withholding window update frames, attackers can cause the server to indefinitely buffer response bodies in memory for stalled streams. This exploitation can lead to unbounded memory growth, causing service degradation, resource exhaustion, or denial-of-service conditions.
Users can update to Proxygen version v2026.07.20.00 or later, where this vulnerability has been addressed.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Jul 23, 2026CISA-ADP
Assessed Jul 23, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/facebook/proxygen/commit/f28742f21f7022c261b7620d4e6b20d82b6cff72 | [email protected] | Source CodeVendor |
Weakness Enumeration
No weakness enumeration is available for this CVE.
Affected Products
| Product | Versions |
|---|---|
| Facebook Proxygen | >= v2017.01.16.00, <= v2026.07.20.00 |
CPE
Remediation
| |
Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 23, 2026 | CVE Modified | CISA-ADP |
| Jul 23, 2026 | New CVE Received | [email protected] |