SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-34752

Prior to version 3.1.4, sending an email with __proto__: as a header name crashes the Haraka worker process.

HIGH 8.7EPSS 0.43%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.43%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Haraka is a Node.js mail server. Prior to version 3.1.4, sending an email with __proto__: as a header name crashes the Haraka worker process. This issue has been patched in version 3.1.4.

CVSS 4.0
8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.43% probability · 37th percentile
CISA KEV
Not listed
Weakness
CWE-248
Affected
haraka project/haraka
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.