CVE-2026-56709 Grav before 3.9.2 Host Header Injection via sendInvitationEmail
Attackers can manipulate Host headers to poison invitation links, redirecting users to malicious domains and bypassing trusted host protections.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-56709?
CVE-2026-56709 is a high-severity vulnerability in getgrav grav, published on 25 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Grav before 3.9.2 fails to validate untrusted Host headers in the sendInvitationEmail() function when constructing token-bearing invitation links. Attackers can manipulate the Host header to poison invitation links and redirect users to attacker-controlled domains, bypassing the require_trusted_host protection which only covers password reset flows.
Weakness: CWE-350
Which versions are affected by CVE-2026-56709?
How do I fix CVE-2026-56709?
No fix has been published for CVE-2026-56709 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-56709 being exploited?
There is no known exploitation of CVE-2026-56709 in the wild and no public exploit code.
Sources
Also known as GHSA-6c2c-797q-5r9x.