UpHeron
All vulnerabilities

Servers and applications

CVE-2009-4418

The unserialize function in PHP 5.3.0 and earlier allows context-dependent attackers to cause a denial of service (resource consumption) via a deeply nested serialized variable, as demonstrated by a string beginning with a:1: followed by many {a:1: sequences.

Severity
Medium 5.0
Published
24 Dec 2009
Last changed
16 Jun 2026
Added to UpHeron
14 Oct 2026
Exploit chance
1% in the next 30 daysHigher than 62% of CVEs. EPSS by FIRST, 12 Nov 2026
Weakness
CWE-189
Attack
Over the network · No login needed
Attacker can
Slow it down
CVSS vector
AV:N/AC:L/Au:N/C:N/I:N/A:P
Sources
NVD

Affected software

SoftwareAffected versions
PHPServers and applications · cpe:a:php:php
  • Version 5.2.11
  • Version 5.2.10
  • Version 5.2.9
  • Version 5.2.8
All 36 release lines
  • Every version up to 5.3.0
  • Version 5.0.0-beta1
  • Version 5.0.0-beta2
  • Version 5.0.0-beta3
  • Version 5.0.0-beta4
  • Version 5.0-rc1
  • Version 5.0.0-rc1
  • Version 5.0-rc2
  • Version 5.0.0-rc2
  • Version 5.0-rc3
  • Version 5.0.0-rc3
  • Version 5
  • Version 5.0.1
  • Version 5.0.2
  • Version 5.0.3
  • Version 5.0.4
  • Version 5.0.5
  • Version 5.1.0
  • Version 5.1.1
  • Version 5.1.2
  • Version 5.1.3
  • Version 5.1.4
  • Version 5.1.5
  • Version 5.1.6
  • Version 5.2.0
  • Version 5.2.1
  • Version 5.2.2
  • Version 5.2.3
  • Version 5.2.4
  • Version 5.2.5
  • Version 5.2.6
  • Version 5.2.7
  • Version 5.2.8
  • Version 5.2.9
  • Version 5.2.10
  • Version 5.2.11

References

  • NVD https://nvd.nist.gov/vuln/detail/CVE-2009-4418
  • CVE.org https://www.cve.org/CVERecord?id=CVE-2009-4418