CVE-2026-6104
published 2026-05-10CVE-2026-6104: 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…
PriorityP349critical9.1CVSS 3.1
AVNACLPRNUINSUCHINAH
EPSS
0.47%
37.1th percentile
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
13 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | php8.4 | — | — |
| php | php | — | — |
| php | php | >= 8.4.0 < 8.4.21 | 8.4.21 |
| php | php | >= 8.5.0 < 8.5.6 | 8.5.6 |
| php_7.4 | php | — | — |
| php_8.2 | php | — | — |
| php_8.3 | php | — | — |
| php_group | php | >= 8.4.* < 8.4.21 | 8.4.21 |
| php_group | php | >= 8.5.* < 8.5.6 | 8.5.6 |
| ubuntu | php8.1 | — | — |
| ubuntu | php8.3 | — | — |
| ubuntu | php8.4 | — | — |
| ubuntu | php8.5 | — | — |
CVSS provenance
nvdv3.19.1CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
nvdv4.06.3MEDIUMCVSS: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:Amber
vendor_ubuntu7.4HIGH
vendor_redhat6.3MEDIUM
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
Ubuntu
PHP vulnerabilities
vendor_ubuntu·2026-05-28·CVSS 7.4
CVE-2026-7259 [HIGH] PHP vulnerabilities
Title: PHP vulnerabilities
Summary: Several security issues were fixed in PHP.
Aleksey Solovev and Nikita Sveshnikov discovered that PHP improperly
handled NUL bytes when preparing SQL queries in the PDO Firebird driver. An
attacker could possibly use this issue to perform SQL injection attacks.
(CVE-2025-14179)
It was discovered that PHP incorrectly handled certain encoding names in
mbstring. An attacker could possibly use this issue to obtain sensitive
information or cause a denial of service. This issue only affected Ubuntu
25.10 and Ubuntu 26.04 LTS. (CVE-2026-6104)
It was discovered that PHP incorrectly handled object references while
parsing crafted SOAP requests. A remote attacker could possibly use this
issue to execute arbitrary code. (CVE-2026-6722)
It was discovered that PH
Red Hat
php: global buffer over-read in mb_convert_encoding() with attacker-supplied encoding
vendor_redhat·2026-05-10·CVSS 6.3
CVE-2026-6104 [MEDIUM] CWE-125 php: global buffer over-read in mb_convert_encoding() with attacker-supplied encoding
php: global buffer over-read in mb_convert_encoding() with attacker-supplied encoding
A flaw was found in PHP. When an encoding name containing an embedded NUL byte is passed to `mb_convert_encoding()` or related mbstring functions, an out-of-bounds read of only 1 byte can occur due to the incorrect processing of string lengths. This issue can cause a denial of service or limited information disclosure.
Statement: This issue is exploited via a crafted encoding passed to `mb_convert_encoding()` without sanitization. The `mb_detect_encoding()`, `mb_convert_variables()` and `mb_detect_order()` functions, as well as the `mbstring.detect_order` and `mbstring.http_output` INI settings are also vulnerable. This vulnerability allows an attacker to cause an out-of-bounds read of only 1 byte, lead
VulDB
PHP up to 8.4.20/8.5.5 out-of-bounds (GHSA-74r9-qxhc-fx53 / Nessus ID 313734)
vuldb·2026-06-02·CVSS 6.3
CVE-2026-6104 [MEDIUM] PHP up to 8.4.20/8.5.5 out-of-bounds (GHSA-74r9-qxhc-fx53 / Nessus ID 313734)
A vulnerability was found in PHP up to 8.4.20/8.5.5. It has been classified as critical. The impacted element is the function mb_convert_encoding/mb_detect_encoding/mb_convert_variables/mb_detect_order. This manipulation causes out-of-bounds read.
The identification of this vulnerability is CVE-2026-6104. It is possible to initiate the attack remotely. There is no exploit available.
Upgrading the affected component is recommended.
No detection rules found.
No public exploits indexed.
2026-05-10
Published