CVE-2026-6103: Phar TAR phar_tar_number() Integer Overflow - Archive Entry Injection
Noroxi assessment
Priority: Monitor (action score 13/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.16% (FIRST EPSS).
- Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: PHP Group PHP 8.2.34, 8.3.35, 8.4.26; azl3 php 8.3.33-1 on Azure Linux 3.0 8.3.35-1.
Low priority for now. Upgrade to PHP Group PHP 8.2.34, 8.3.35, 8.4.26; azl3 php 8.3.33-1 on Azure Linux 3.0 8.3.35-1 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
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.
- Published
- Sep 25, 2026
- Updated
- Oct 23, 2026
- EPSS
- 0.1% · 5th percentile
- CWE
- CWE-190
Report tools
Action score
13
Monitor
Low priority for now.
- CVSS
- 13 / 40 · 3.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.1%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 3.3
- CNA · php
- 4.3
- 1.0 point gap
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| php | php | cpe:2.3:a:php:php |
Using php? Add it to your stack and be the first to know about CVEs like this one. (PHP)
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- php php8.2.0 and later · before 8.2.34
- php php8.3.0 and later · before 8.3.35
- php php8.4.0 and later · before 8.4.26
- php php8.5.0 and later · before 8.5.11
Versions reported by the vendor
Affected version ranges reported by the assigning authority (php). Independent of NVD's CPE analysis and usually ahead of it.
PHP Group PHP
- 8.2.* and later · before 8.2.34affected · semver
- 8.3.* and later · before 8.3.35affected · semver
- 8.4.* and later · before 8.4.26affected · semver
- 8.5.* and later · before 8.5.11affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:8 | apcu-panel | before 5.1.18-1.module_el8.6.0+2750+78feabcb | 5.1.18-1.module_el8.6.0+2750+78feabcb |
| AlmaLinux:8 | libzip | before 1.6.1-1.module_el8.6.0+2750+78feabcb | 1.6.1-1.module_el8.6.0+2750+78feabcb |
| AlmaLinux:8 | libzip | before 1.6.1-1.module_el8.10.0+3935+28808425 | 1.6.1-1.module_el8.10.0+3935+28808425 |
| AlmaLinux:8 | libzip | before 1.6.1-1.module_el8.6.0+3239+bedf0508 | 1.6.1-1.module_el8.6.0+3239+bedf0508 |
| AlmaLinux:8 | libzip-devel | before 1.6.1-1.module_el8.10.0+3935+28808425 | 1.6.1-1.module_el8.10.0+3935+28808425 |
| AlmaLinux:8 | libzip-devel | before 1.6.1-1.module_el8.6.0+3239+bedf0508 | 1.6.1-1.module_el8.6.0+3239+bedf0508 |
| AlmaLinux:8 | libzip-devel | before 1.6.1-1.module_el8.6.0+2750+78feabcb | 1.6.1-1.module_el8.6.0+2750+78feabcb |
| AlmaLinux:8 | libzip-tools | before 1.6.1-1.module_el8.10.0+3935+28808425 | 1.6.1-1.module_el8.10.0+3935+28808425 |
| AlmaLinux:8 | libzip-tools | before 1.6.1-1.module_el8.6.0+3239+bedf0508 | 1.6.1-1.module_el8.6.0+3239+bedf0508 |
| AlmaLinux:8 | php | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-bcmath | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-cli | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-common | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-dba | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-dbg | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-devel | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-embedded | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-enchant | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-ffi | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-fpm | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-gd | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-gmp | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-intl | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-json | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
+96
Same product
php: all recordsOther highest-scoring records for the same primary product.
- CVE-2024-4577Argument Injection in PHP-CGIKEV99Now
- CVE-2019-11043Underflow in PHP-FPM can lead to RCEKEV99Now
- CVE-2012-1823sapi/cgi/cgi_main.c in PHP before 5.3.12 and 5.4.x before 5.4.2, when configured as a CGI script (aka php-cgi), does not properly handle queKEV99Now
Published before and after this one in the same product
- ← EarlierCVE-2025-1218Sep 25, 2026 · Various packet overreads in mysqlnd_writeprotocol.c23Monitor
- ← EarlierCVE-2026-17545Sep 25, 2026 · PHP on Windows: Reserved Device Names Are Not Rejected Before File/Stream I/O which can cause DoS27Monitor
- Later →CVE-2026-91765Sep 25, 2026 · SOAP: Unbounded Recursion in Server-Side cleanup_xml_node30Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| PHP Group PHP | 8.2.34 | Vendor (CNA) |
| PHP Group PHP | 8.3.35 | Vendor (CNA) |
| PHP Group PHP | 8.4.26 | Vendor (CNA) |
| PHP Group PHP | 8.5.11 | Vendor (CNA) |
| azl3 php 8.3.33-1 on Azure Linux 3.0 | 8.3.35-1 · Release Notes | Microsoft (MSRC) |
| almalinux:apcu-panel | 5.1.18-1.module_el8.6.0+2750+78feabcb · AlmaLinux:8 | Package registry (OSV) |
| almalinux:libzip | 1.6.1-1.module_el8.6.0+2750+78feabcb · AlmaLinux:8 | Package registry (OSV) |
| almalinux:libzip-devel | 1.6.1-1.module_el8.10.0+3935+28808425 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:libzip-tools | 1.6.1-1.module_el8.10.0+3935+28808425 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:php | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb · AlmaLinux:8 | Package registry (OSV) |
| almalinux:php-bcmath | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb · AlmaLinux:8 | Package registry (OSV) |
| almalinux:php-cli | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb · AlmaLinux:8 | Package registry (OSV) |
| almalinux:php-common | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb · AlmaLinux:8 | Package registry (OSV) |
| almalinux:php-dba | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb · AlmaLinux:8 | Package registry (OSV) |
| almalinux:php-dbg | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb · AlmaLinux:8 | Package registry (OSV) |
| almalinux:php-devel | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb · AlmaLinux:8 | Package registry (OSV) |
| almalinux:php-embedded | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb · AlmaLinux:8 | Package registry (OSV) |
| debian:php8.2 | 8.2.34-1~deb12u1 · Debian:12 | Package registry (OSV) |
| debian:php8.4 | 8.4.26-1~deb13u1 · Debian:13 | Package registry (OSV) |
| opensuse:apache2-mod_php8 | 8.4.26-160000.1.1 · openSUSE:Leap 16.0 | Package registry (OSV) |
| opensuse:php8 | 8.5.11-1.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| opensuse:php8-embed | 8.4.26-160000.1.1 · openSUSE:Leap 16.0 | Package registry (OSV) |
| opensuse:php8-fastcgi | 8.4.26-160000.1.1 · openSUSE:Leap 16.0 | Package registry (OSV) |
| opensuse:php8-fpm | 8.4.26-160000.1.1 · openSUSE:Leap 16.0 | Package registry (OSV) |
| opensuse:php8-test | 8.4.26-160000.1.1 · openSUSE:Leap 16.0 | Package registry (OSV) |
| red hat:php | 0:8.5.11-2.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:php-bcmath | 0:8.5.11-2.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:php-cli | 0:8.5.11-2.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:php-common | 0:8.5.11-2.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:php-dba | 0:8.5.11-2.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
+31
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- @OSTIF-Derek (GitHub)reporter
- Jakub Zelenkaremediation developer
- Weilin Duremediation reviewer
- @arnoldasr (GitHub)reporter
- @Oblivionsage (GitHub)reporter
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2025-14178272 days apartHeap buffer overflow in array_merge()32Monitor
- CVE-2025-141810 days apartInteger overflow to buffer overflow in soap HTTP parsing26Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- low · data or configuration can be modified
- Availability
- none
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- Low
- Availability impact
- None
Weakness class (CWE)
CWE-190 · Integer Overflow or WraparoundCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- CVSS4.3 → 3.3
- Severitymedium → low
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →