Vulnerability in Newsletter

CVE-2026-86824

The Newsletter WordPress plugin before 9.3.8 does not generate its email tracking signing key with sufficient entropy and signs its tracking links with an unkeyed hash, allowing an unauthenticated attacker who recovers that key offline to forge tracking links, obtain any subscriber's session token, and read and modify that subscriber's stored personal data.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (4.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 4th percentile — 4.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-86824: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

  • Newsletter

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-86824?
CVE-2026-86824 is a medium-severity vulnerability in Newsletter, classified under Inadequate Encryption Strength. CVSS score: 4.8/10. Published 2026-09-17.
How severe is CVE-2026-86824?
Medium severity. CVSS v3 base score is 4.8 out of 10.