IPv6 ACL bypass in FastCGI listen.allowed_clients due to partial address comparison (memcmp 12 bytes)
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.
BIT-libphp-2026-91768
Primary source · Revision 2
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:BIT-libphp-2026-91768
libphp
Source reference: /affected/0/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 8.2.34
Source reference:
/affected/0/ranges8.3.35Source reference:
/affected/0/ranges8.4.26Source reference:
/affected/0/ranges8.5.11Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "8.2.0"
},
{
"fixed": "8.2.34"
},
{
"introduced": "8.3.0"
},
{
"fixed": "8.3.35"
},
{
"introduced": "8.4.0"
},
{
"fixed": "8.4.26"
},
{
"introduced": "8.5.0"
},
{
"fixed": "8.5.11"
}
]
}
],
"package": {
"name": "libphp",
"purl": "pkg:bitnami/libphp",
"ecosystem": "Bitnami"
},
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"
}
],
"database_specific": {
"source": "https://github.com/bitnami/vulndb/tree/main/data/libphp/BIT-libphp-2026-91768.json"
}
}
]- Related CVEs
- CVE-2026-91768
Source reference:
/aliases
Publisher severity
medium
Source reference: /database_specific/severity
- Event
- #59692 · Revision 2
- Added to Heist Feed
- Publisher date