Vulnerability · Published Sep 25, 2026 · Assigned by php
CVE-2026-6103Phar TAR phar_tar_number() Integer Overflow - Archive Entry Injection
Medium 4.3
In plain English
A medium-severity integer overflow in PHP from PHP Group. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 5% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)4.3Medium
Exploit odds (30 days)0.2%top 94.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
phar_tar_number() parses the octal size field of a TAR header into a uint32_t with no overflow check. The field is 11 octal digits wide and holds values up to 0x1FFFFFFFF, so a size above 0xFFFFFFFF silently wraps. The parser then skips the wrong number of data blocks and interprets attacker-controlled file content as the next TAR header, which lets a crafted archive inject entries that PharData reports and extracts as if they were genuine.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | apcu-panel | 5.1.18-1.module_el8.6.0+2750+78feabcb | ALSA-2026:87080 |
| AlmaLinux:8 | libzip | 1.6.1-1.module_el8.6.0+3239+bedf0508 | ALSA-2026:87080 |
| AlmaLinux:8 | libzip | 1.6.1-1.module_el8.6.0+2750+78feabcb | ALSA-2026:87080 |
| AlmaLinux:8 | libzip | 1.6.1-1.module_el8.10.0+3935+28808425 | ALSA-2026:87080 |
| AlmaLinux:8 | libzip-devel | 1.6.1-1.module_el8.6.0+2750+78feabcb | ALSA-2026:87080 |
| AlmaLinux:8 | libzip-devel | 1.6.1-1.module_el8.10.0+3935+28808425 | ALSA-2026:87080 |
| AlmaLinux:8 | libzip-devel | 1.6.1-1.module_el8.6.0+3239+bedf0508 | ALSA-2026:87080 |
| AlmaLinux:8 | libzip-tools | 1.6.1-1.module_el8.10.0+3935+28808425 | ALSA-2026:87080 |
| AlmaLinux:8 | libzip-tools | 1.6.1-1.module_el8.6.0+3239+bedf0508 | ALSA-2026:87080 |
| AlmaLinux:8 | php | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-bcmath | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-cli | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-common | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-dba | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-dbg | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-devel | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-embedded | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-enchant | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-ffi | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-fpm | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-gd | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-gmp | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-intl | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-json | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-ldap | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-mbstring | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-mysqlnd | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-odbc | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-opcache | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-pdo | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-pear | 1:1.10.13-1.module_el8.10.0+3935+28808425 | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-apcu | 5.1.18-1.module_el8.10.0+3935+28808425 | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-apcu | 5.1.18-1.module_el8.6.0+2750+78feabcb | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-apcu-devel | 5.1.18-1.module_el8.6.0+2750+78feabcb | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-apcu-devel | 5.1.18-1.module_el8.10.0+3935+28808425 | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-rrd | 2.0.1-1.module_el8.6.0+2750+78feabcb | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-rrd | 2.0.1-1.module_el8.6.0+3239+bedf0508 | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-rrd | 2.0.1-1.module_el8.10.0+3935+28808425 | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-xdebug | 2.9.5-1.module_el8.6.0+3239+bedf0508 | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-xdebug | 2.9.5-1.module_el8.6.0+2750+78feabcb | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-zip | 1.18.2-1.module_el8.6.0+2750+78feabcb | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-zip | 1.18.2-1.module_el8.10.0+3935+28808425 | ALSA-2026:87080 |
| AlmaLinux:8 | php-pecl-zip | 1.18.2-1.module_el8.6.0+3239+bedf0508 | ALSA-2026:87080 |
| AlmaLinux:8 | php-pgsql | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-process | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-snmp | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-soap | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-xml | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux:8 | php-xmlrpc | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| Alpine:v3.22 | php82 | 8.2.35-r0 | ALPINE-CVE-2026-6103 |
| Alpine:v3.22 | php83 | 8.3.36-r0 | ALPINE-CVE-2026-6103 |
| Alpine:v3.23 | php83 | 8.3.36-r0 | ALPINE-CVE-2026-6103 |
| Alpine:v3.24 | php83 | 8.3.35-r0 | ALPINE-CVE-2026-6103 |
| Alpine:v3.22 | php84 | 8.4.27-r0 | ALPINE-CVE-2026-6103 |
| Alpine:v3.23 | php84 | 8.4.27-r0 | ALPINE-CVE-2026-6103 |
| Alpine:v3.24 | php84 | 8.4.26-r0 | ALPINE-CVE-2026-6103 |
| Alpine:v3.23 | php85 | 8.5.12-r0 | ALPINE-CVE-2026-6103 |
| Alpine:v3.24 | php85 | 8.5.11-r0 | ALPINE-CVE-2026-6103 |
| Debian:12 | php8.2 | 8.2.34-1~deb12u1 | DEBIAN-CVE-2026-6103 |
| Debian:13 | php8.4 | 8.4.26-1~deb13u1 | DEBIAN-CVE-2026-6103 |
| Debian:14 | php8.4 | 8.4.26-1 | DEBIAN-CVE-2026-6103 |
| Rocky Linux:8 | libzip | 0:1.6.1-1.module+el8.10.0+1604+6558efc7 | RLSA-2026:87080 |
| Rocky Linux:8 | libzip | 0:1.6.1-1.module+el8.10.0+1912+72767185 | RLSA-2026:87080 |
| Rocky Linux:8 | php | 0:7.4.33-8.module+el8.10.0+40393+c071e357 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pear | 1:1.10.13-1.module+el8.10.0+1605+02e07af7 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pear | 1:1.10.13-1.module+el8.10.0+1912+72767185 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pear | 1:1.10.13-1.module+el8.10.0+1604+6558efc7 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pecl-apcu | 0:5.1.18-1.module+el8.10.0+1604+6558efc7 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pecl-apcu | 0:5.1.18-1.module+el8.10.0+1912+72767185 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pecl-rrd | 0:2.0.1-1.module+el8.10.0+1604+6558efc7 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pecl-rrd | 0:2.0.1-1.module+el8.4.0+414+2e7afcdd | RLSA-2026:87080 |
| Rocky Linux:8 | php-pecl-rrd | 0:2.0.1-1.module+el8.10.0+1912+72767185 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pecl-xdebug | 0:2.9.5-1.module+el8.10.0+1912+72767185 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pecl-xdebug | 0:2.9.5-1.module+el8.10.0+1604+6558efc7 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pecl-zip | 0:1.18.2-1.module+el8.10.0+1604+6558efc7 | RLSA-2026:87080 |
| Rocky Linux:8 | php-pecl-zip | 0:1.18.2-1.module+el8.10.0+1912+72767185 | RLSA-2026:87080 |
| Ubuntu:22.04:LTS | php8.1 | 8.1.2-1ubuntu2.27 | USN-8936-1 |
| Ubuntu:22.04:LTS | php8.1 | 8.1.2-1ubuntu2.27 | UBUNTU-CVE-2026-6103 |
| Ubuntu:24.04:LTS | php8.3 | 8.3.6-0ubuntu0.24.04.12 | UBUNTU-CVE-2026-6103 |
| Ubuntu:24.04:LTS | php8.3 | 8.3.6-0ubuntu0.24.04.12 | USN-8936-1 |
| Ubuntu:26.04:LTS | php8.5 | 8.5.4-0ubuntu1.4 | UBUNTU-CVE-2026-6103 |
| Ubuntu:26.04:LTS | php8.5 | 8.5.4-0ubuntu1.4 | USN-8936-1 |
| Ubuntu:26.10 | php8.5 | 8.5.9-0ubuntu2 | UBUNTU-CVE-2026-6103 |
| Ubuntu:26.10 | php8.5 | 8.5.9-0ubuntu2 | USN-8936-1 |
Affected products (as reported)
Weakness: CWE-190 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N