by Kastro CVE-2026-6104
PHP Group PHP — Global buffer over-read in mb_convert_encoding() with attacker-supplied encoding
Description · from the CVE record
In PHP versions 8.4.* before 8.4.21 and 8.5.* before 8.5.6, when an encoding name containing an embedded NUL byte is passed to mb_convert_encoding() or related mbstring functions, the code incorrectly assumes that when strncasecmp() returns 0 it means the strings have the same length. This can lead to out-of-bounds read of global memory, potentially causing a crash or information disclosure or crash. Affected functions include mb_convert_encoding(), mb_detect_encoding(), mb_convert_variables(), and mb_detect_order(), as well as the mbstring.detect_order and mbstring.http_output INI settings.
Affected
ProductAffectedFixed inSource
PHP8.4.* – < 8.4.218.4.21CNA
PHP8.5.* – < 8.5.68.5.6CNA
Red Hat Enterprise Linux 10see advisory0:8.4.21-1.el10_2redhat-SADP
Red Hat Enterprise Linux 10see advisory–redhat-SADP
Red Hat Enterprise Linux 6see advisory–redhat-SADP
Red Hat Enterprise Linux 7see advisory–redhat-SADP
Red Hat Enterprise Linux 8see advisory–redhat-SADP
Red Hat Enterprise Linux 8see advisory–redhat-SADP
Red Hat Enterprise Linux 9see advisory–redhat-SADP
Red Hat Enterprise Linux 9see advisory–redhat-SADP
Red Hat Enterprise Linux 9see advisory–redhat-SADP
Red Hat Hardened Imagessee advisory–redhat-SADP
Scores by source
NVD9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
redhat-SADP (CNA)8.2CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
php (CNA)6.3CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:L/SI:N/SA:L/RE:M/U:Amber
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: partial