CVE-2015-6834PHP Use-After-Free
php5 - security update
Published Nov 8, 2015 · Updated Apr 22, 2026 · Also known as DEBIAN-CVE-2015-6835, DSA-3358-1, UBUNTU-CVE-2015-6834
Key Facts
Patch immediately- CVE-2015-6834 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting PHP, php5 (debian), php54-bcmath (amazon) and 22 more products.
- It is not listed in any known-exploited vulnerabilities catalog. A public exploit is reported by tracking sources, but no code link is listed yet.
- EPSS estimates a 47% probability of exploitation in the next 30 days.
- Fixed versions are available, including apache2-mod_php5 5.5.14-36.1, PHP 5.4.44, php5 5.3.3.1-7+squeeze28.
- Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.
Scores
CVSS v3.1
9.8
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
47%
Higher than 98.8% of all scored CVEs
Exploit maturity
Proof of concept
ATLAS score
52/100
Publication score, see How it works
Exploitation Verdict
KEV listed
Not listed
Federal due date
None
No federal due date
Ransomware use
Not reported
Attributed actors
None named
Exploit & Defence Guidance
Exploit maturity
Proof of concept
Public exploit code
2
Proof-of-concept links
In-the-wild evidence
0
Reports of active use
Advisories And Exploit References
Description
Multiple use-after-free vulnerabilities in PHP before 5.4.45, 5.5.x before 5.5.29, and 5.6.x before 5.6.13 allow remote attackers to execute arbitrary code via vectors related to (1) the Serializable interface, (2) the SplObjectStorage class, and (3) the SplDoublyLinkedList class, which are mishandled during unserialization.
Affected Products
191 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| PHPPHP | 5.5.0, 5.5.1, 5.5.10, 5.5.11, 5.5.12, 5.5.13, 5.5.14, 5.5.15 | 5.4.44 |
| php5debian | See advisory | 5.3.3.1-7+squeeze28 |
| php54-bcmathamazon | See advisory | 5.4.45-1.75.amzn1 |
| php54-cliamazon | See advisory | 5.4.45-1.75.amzn1 |
| php54-commonamazon | See advisory | 5.4.45-1.75.amzn1 |
Patched Releases
apache2-mod_php5
5.5.14-36.1
PHP
5.4.44
php5
5.3.3.1-7+squeeze28, 5.4.45-0+deb7u1, 5.5.14-36.1, 5.5.9+dfsg-1ubuntu4.13, 5.6.13+dfsg-0+deb8u1
php5-bcmath
5.5.14-36.1
php5-bz2
5.5.14-36.1
php5-calendar
5.5.14-36.1
php5-ctype
5.5.14-36.1
php5-curl
5.5.14-36.1
php5-dba
5.5.14-36.1
php5-devel
5.5.14-36.1
php5-dom
5.5.14-36.1
php5-enchant
5.5.14-36.1
php5-exif
5.5.14-36.1
php5-fastcgi
5.5.14-36.1
php5-fileinfo
5.5.14-36.1
php5-fpm
5.5.14-36.1
php5-ftp
5.5.14-36.1
php5-gd
5.5.14-36.1
php5-gettext
5.5.14-36.1
php5-gmp
5.5.14-36.1
php5-iconv
5.5.14-36.1
php5-intl
5.5.14-36.1
php5-json
5.5.14-36.1
php5-ldap
5.5.14-36.1
php5-mbstring
5.5.14-36.1
Timeline
Publicly disclosed
Nov 8, 2015
Last updated
Apr 22, 2026
Weakness Type
- CWE-416 Use After Free
References
- advisoryubuntu.com · CVE-2015-6834
- advisorycve.org · CVERecord
- advisoryRHSA-2016:0457
- advisorybugzilla.suse.com · 935074
- advisorybugzilla.suse.com · 942291
FAQ
Common Questions.
Multiple use-after-free vulnerabilities in PHP before 5.4.45, 5.5.x before 5.5.29, and 5.6.x before 5.6.13 allow remote attackers to execute arbitrary code via vectors related to (1) the Serializable interface, (2) the SplObjectStorage class, and (3) the SplDoublyLinkedList class, which are mishandled during unseriali…
Affected: PHP versions 5.5.0, 5.5.1, 5.5.10, 5.5.11, 5.5.12, 5.5.13, 5.5.14, 5.5.15; php5 (debian); php54-bcmath (amazon), among others. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
A public exploit is reported by tracking sources, but no code link is listed yet.
Fixed versions are available, including apache2-mod_php5 5.5.14-36.1, PHP 5.4.44, php5 5.3.3.1-7+squeeze28.
Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.
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