What is CVE-2026-91831?

CVE-2026-91831 is a low-severity vulnerability in Subscribe To Comments, classified under CRLF Injection. CVSS score: 3.8/10. Published 2026-10-19.

How severe is CVE-2026-91831?

Low severity. CVSS v3 base score is 3.8 out of 10.

Vulnerability in Subscribe To Comments

CVE-2026-91831

The Subscribe to Comments WordPress plugin before 2.3.3 does not sanitise newline characters from a notification sender-name setting before using it in e-mail headers, allowing users with Author-level access and above to inject arbitrary e-mail headers, such as a hidden Bcc, and to spoof the sender.

Vulnerability class: CRLF Injection

Published 2026-10-19 · last modified 2026-10-19.

CVSS v3 metric

CVSS v3 base score 3.8 (Low). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Subscribe To Comments

Weakness classification (CWE)

CWE-93 — CRLF Injection

References

wpscan.com/vulnerability/6cd60f78-f5e2-4b4a-8d50-7d2bc4f981ee/ (technical-description, exploit, vdb-entry)

Frequently asked questions

What is CVE-2026-91831?: CVE-2026-91831 is a low-severity vulnerability in Subscribe To Comments, classified under CRLF Injection. CVSS score: 3.8/10. Published 2026-10-19.
How severe is CVE-2026-91831?: Low severity. CVSS v3 base score is 3.8 out of 10.