CVE-2026-91768

EUVD-2026-87350
The IPv6 branch of the FastCGI client access check compares only the first 12 bytes of a 16-byte IPv6 address, so listen.allowed_clients matches on a /96 prefix instead of the exact address. An attacker who can source an address sharing the first 96 bits with an allowed one passes the check and reaches the FastCGI endpoint.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
phpCNA
6.5 MEDIUM
ADJACENT_NETWORK
LOW
NONE
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
phpphp
8.2.* ≤
𝑥
< 8.2.34
CNA
phpphp
8.3.* ≤
𝑥
< 8.3.35
CNA
phpphp
8.4.* ≤
𝑥
< 8.4.26
CNA
phpphp
8.5.* ≤
𝑥
< 8.5.11
CNA
Debian logo
Debian Releases
Debian Product
Codename
php8.2
bookworm
vulnerable
bookworm (security)
vulnerable
php8.4
forky
vulnerable
sid
vulnerable
trixie
vulnerable
trixie (security)
8.4.26-1~deb13u1
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
php5
jammy
dne
noble
dne
resolute
dne
trusty
needs-triage
php7.0
jammy
dne
noble
dne
resolute
dne
xenial
needs-triage
php7.2
bionic
needs-triage
jammy
dne
noble
dne
resolute
dne
php7.4
focal
needs-triage
jammy
dne
noble
dne
resolute
dne
php8.1
jammy
needs-triage
noble
dne
resolute
dne
php8.3
jammy
dne
noble
needs-triage
resolute
dne
php8.5
jammy
dne
noble
dne
resolute
needs-triage