CVE-2015-6834

critical
Published 2016-05-16 ยท Modified 2026-05-06
CVSS v3
9.8
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4 NEW
โ€”
not yet in upstream
VIR risk
10.0

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.

Predictions

Exploit likelihood
97%
Patch ETA
โ€”

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or โ€” if you've already worked around this in production โ€” publish your fix to the community-verified tier.

โœš Propose a mitigation on Community โ†’ Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

Exploits

Public proof-of-concept code below. AS-IS, for defenders and authorised testing only.

Exploit-DB

EDB-38120 dos php verified
Taoguang Chen ยท 2015-09-09

PHP 5.4/5.5/5.6 - SplDoublyLinkedList 'Unserialize()' Use-After-Free

Source code queued for fetch โ€” refresh in a moment.
EDB-38122 dos php verified
Taoguang Chen ยท 2015-09-09

PHP 5.4/5.5/5.6 - SplObjectStorage 'Unserialize()' Use-After-Free

Source code queued for fetch โ€” refresh in a moment.

Application impact

VendorProductVersionsFixed
php phpphp{"endIncluding":"5.4.44"}
php phpphp5.5.0
php phpphp5.5.1
php phpphp5.5.2
php phpphp5.5.3
php phpphp5.5.4
php phpphp5.5.5
php phpphp5.5.6
php phpphp5.5.7
php phpphp5.5.8
php phpphp5.5.9
php phpphp5.5.10
php phpphp5.5.11
php phpphp5.5.12
php phpphp5.5.13
php phpphp5.5.14
php phpphp5.5.15
php phpphp5.5.16
php phpphp5.5.17
php phpphp5.5.18
php phpphp5.5.19
php phpphp5.5.20
php phpphp5.5.21
php phpphp5.5.22
php phpphp5.5.23
php phpphp5.5.24
php phpphp5.5.25
php phpphp5.5.26
php phpphp5.5.27
php phpphp5.5.28
php phpphp5.6.0
php phpphp5.6.1
php phpphp5.6.2
php phpphp5.6.3
php phpphp5.6.4
php phpphp5.6.5
php phpphp5.6.6
php phpphp5.6.7
php phpphp5.6.8
php phpphp5.6.9
php phpphp5.6.10
php phpphp5.6.11
php phpphp5.6.12

References

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.