All vulnerabilities

Servers and applications

CVE-2017-8923

The zend_string_extend function in Zend/zend_string.h in PHP through 7.1.5 does not prevent changes to string objects that result in a negative length, which allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact by leveraging a script's use of .= with a long string.

Severity
Critical 9.8
Published
12 May 2017
Last changed
17 Jun 2026
Added to UpHeron
14 Oct 2026
Fixed in
7.4.24, 8.0.11
Sources
NVD

Affected software

SoftwareAffected versions
PHPServers and applications · cpe:a:php:php
  • Every version before 7.4.24
  • From 8.0.0 before 8.0.11

References

  • NVD https://nvd.nist.gov/vuln/detail/CVE-2017-8923
  • CVE.org https://www.cve.org/CVERecord?id=CVE-2017-8923