CVE-2026-6103

Publication date 25 September 2026

Last updated 26 October 2026

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

4.3 · Medium

Score breakdown

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.

Read the notes from the security team

Status

Package Ubuntu Release Status
php5 26.10 stonking Not in release
26.04 LTS resolute Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
14.04 LTS trusty
Fixed in 5.5.9+dfsg-1ubuntu4.29+esm17
php7.0 26.10 stonking Not in release
26.04 LTS resolute Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
16.04 LTS xenial
Fixed in 7.0.33-0ubuntu0.16.04.16+esm21
php7.2 26.10 stonking Not in release
26.04 LTS resolute Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
18.04 LTS bionic
Fixed in 7.2.24-0ubuntu0.18.04.17+esm13
php7.4 26.10 stonking Not in release
26.04 LTS resolute Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal
Fixed in 7.4.3-4ubuntu2.29+esm4
php8.1 26.10 stonking Not in release
26.04 LTS resolute Not in release
24.04 LTS noble Not in release
22.04 LTS jammy
Fixed in 8.1.2-1ubuntu2.27
php8.3 26.10 stonking Not in release
26.04 LTS resolute Not in release
24.04 LTS noble
Fixed in 8.3.6-0ubuntu0.24.04.12
22.04 LTS jammy Not in release
php8.5 26.10 stonking
Fixed in 8.5.9-0ubuntu2
26.04 LTS resolute
Fixed in 8.5.4-0ubuntu1.4
24.04 LTS noble Not in release
22.04 LTS jammy Not in release

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Notes

sbeattie

PEAR issues should go against php-pear as of xenial PEAR issues should go against php-pear as of xenial

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
php8.3
php8.5

Severity score breakdown

CVSS version: CVSS v3.0

Base score 4.3 · Medium

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

References

Related Ubuntu Security Notices (USN)

Other references

Access our resources on patching vulnerabilities