CVE-2019-11921
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.08%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.0
- 9.8 CRITICALCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 2.08% probability · 81th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-787
- Affected
- facebook/proxygen
- Source
- cve-assign@fb.com
EPSS 2.1% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/facebook/proxygen/commit/2f07985bef9fbae124cc63e5c0272e32da4fdaecPatch, Third Party Advisory
- https://www.facebook.com/security/advisories/cve-2019-11921Third Party Advisory
- https://github.com/facebook/proxygen/commit/2f07985bef9fbae124cc63e5c0272e32da4fdaecPatch, Third Party Advisory
- https://www.facebook.com/security/advisories/cve-2019-11921Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.