CVE-2026-6104

criticalpriority · track · 36EPSS 0.005 · 40 %ileDEEURUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.47% (40th) EPSS
CVSS 9.1 · critical
Is it mine?
37 products
Check your exposure
Who says so?
5 sources
cnnvd · enisa_euvd · fstec_bdu · osv

EPSS · scored 2026-10-27

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.

01

cvss

Technical severity, 0–10. One row per scoring source.

9.1
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–critical · 1.7–9.1

v3.19.1criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 5.2
v3.18.2highAV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:Hsecondary · FSTEC (BDU) RU
v3.18.2highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:Hsecondaryexploitability 3.9 · impact 4.2
v4.06.3mediumCVSS: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:Ambersecondary · ENISA EU
v4.06.3mediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:L/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:M/U:Ambersecondary · security@php.net
v4.01.7lowCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:L/SI:N/SA:L/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:M/U:Ambersecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-125USCWE-125US
04

affected products (37)

Products and version ranges known to be affected.

showing 20 of 37
05

advisories (5)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2026-1433PHP: Mehrere SchwachstellenDeutsch2026-05-07csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen in PHP ausnutzen, um beliebigen Programmcode auszuführen, SQL-Injection- oder Cross-Site-Scripting-Angriffe durchzuführen, Daten zu manipulieren, vertrauliche Informationen offenzulegen oder einen Denial-of-Service-Zustand zu verursachen.

  • WID-SEC-W-2026-2455Oracle Solaris Drittanbieterkomponenten: Mehrere SchwachstellenDeutsch2026-07-21csaf · cert_bundDE

    Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in verschiedenen Komponenten von Drittanbietern in Oracle Solaris ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen.

  • BIT-libphp-2026-6104Global buffer over-read in mb_convert_encoding() with attacker-supplied encoding2026-05-12vendor · osvUS

    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.

  • BIT-php-2026-6104Global buffer over-read in mb_convert_encoding() with attacker-supplied encoding2026-05-12vendor · osvUS

    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.

  • BIT-php-min-2026-6104Global buffer over-read in mb_convert_encoding() with attacker-supplied encoding2026-05-12vendor · osvUS

    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.

06

also known as (6)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bduosvcert_bundNVDCVE.orgMITRE
published 2026-05-10modified 2026-09-01
08

references (8)

External citations — patches, advisories, analysis.

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