CVE-2026-91831 Subscribe to Comments 2.3 - 2.3.2 - Author+ Email Header Injection via From Name Setting
Authors can inject email headers via the sender name setting, enabling hidden BCCs and sender spoofing in the Subscribe to Comments plugin.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-91831?
CVE-2026-91831 is a low-severity vulnerability in Unknown Subscribe to Comments, published on 19 Oct 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
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.
Weakness: CWE-93
Which versions are affected by CVE-2026-91831?
How do I fix CVE-2026-91831?
No fix has been published for CVE-2026-91831 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-91831 being exploited?
There is no known exploitation of CVE-2026-91831 in the wild and no public exploit code.
Sources
Also known as GHSA-fwc8-9qp3-8f5c.