VDB
CVE-2026-6104
CVE-2026-6104
PUBLISHED
CVSS 6.3 MEDIUM
Reported by php · Published May 10, 2026
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.
EPSS 0.02% · 6.2th percentile
Risk Scores
CVSS v4.0
6.3
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
EPSS Score
0.02%
6.2th percentile
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| PHP Group | PHP | 8.4.*, 8.5.* |
| PHP Group | PHP | 8.4.*, 8.5.* |
Timeline
- May 8, 2026 PoC Published
- May 10, 2026 EPSS Score
- May 10, 2026 CVE Published
- May 11, 2026 Security Advisory
- May 18, 2026 EPSS Score
- May 19, 2026 EPSS Score
- May 20, 2026 EPSS Score
- May 21, 2026 EPSS Score
- May 22, 2026 EPSS Score
- May 23, 2026 EPSS Score
- May 24, 2026 EPSS Score
- May 25, 2026 EPSS Score