CVE-2019-11921

9.8 criticalEPSS 2.1%

Critical (9.8) in facebook proxygen. EPSS 2.1% chance of exploitation in the next 30 days.

An out of bounds write is possible via a specially crafted packet in certain configurations of Proxygen due to improper handling of Base64 when parsing malformed binary content in Structured HTTP Headers. This issue affects versions of proxygen prior to v2019.07.22.00.

Severity

CVSS 3.0

9.8 critical

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS: 2.1% chance of exploitation in the next 30 days; higher than 81% of CVEs (scores of 2026-10-31)
CWE: CWE-787
Published: 2019-07-25
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

facebook:proxygen

References

https://github.com/facebook/proxygen/commit/2f07985bef9fbae124cc63e5c0272e32da4fdaec
https://www.facebook.com/security/advisories/cve-2019-11921
https://github.com/facebook/proxygen/commit/2f07985bef9fbae124cc63e5c0272e32da4fdaec
https://www.facebook.com/security/advisories/cve-2019-11921

Check your stack JSON