What is CVE-2026-34752?

CVE-2026-34752 is a high-severity vulnerability in Haraka, classified under CWE-248. CVSS score: 7.5/10. Published 2026-04-02.

How severe is CVE-2026-34752?

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

Vulnerability in Haraka

CVE-2026-34752

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.

Published 2026-04-02 · last modified 2026-07-24.

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.

EPSS exploit prediction

EPSS: 0.005 (41.6th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 41.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001

Affected products

Haraka — versions < 3.1.4
Haraka Project

Weakness classification (CWE)

CWE-248

References

github.com/haraka/Haraka/security/advisories/GHSA-xph3-r2jf-4vp3 (Exploit, Vendor Advisory)
github.com/haraka/Haraka/releases/tag/v3.1.4 (Release Notes)

Frequently asked questions

What is CVE-2026-34752?: CVE-2026-34752 is a high-severity vulnerability in Haraka, classified under CWE-248. CVSS score: 7.5/10. Published 2026-04-02.
How severe is CVE-2026-34752?: High severity. CVSS v3 base score is 7.5 out of 10.