CVE-2026-6104
CVSS: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
Summary
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 Software
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| PHP Group | PHP | 8.4.* < 8.4.21 | affected |
| PHP Group | PHP | 8.5.* < 8.5.6 | affected |
Weaknesses
- CWE-125: CWE-125 Out-of-bounds Read
ADP Enrichment
CISA ADP Vulnrichment
- SSVC:
- Exploitation: none
- Automatable: yes
- Technical Impact: partial
php: global buffer over-read in mb_convert_encoding() with attacker-supplied encoding
Additional References
- https://access.redhat.com/security/cve/CVE-2026-6104
- https://bugzilla.redhat.com/show_bug.cgi?id=2468573
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6104.json
- https://access.redhat.com/errata/RHSA-2026:22649
References
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