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TI-2017-06415 Aliases CVE-2017-8923GHSA-wrc8-jp87-rq8j

The zend_string_extend function in Zend/zend_string.h in PHP through 7.1.5 does not…

Priority MEDIUM 52CWE-787Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 1 fixed, 2 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-787 and the CVSS impact.

Summary

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.

Why it matters now

EPSS 0.07191 94th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial Red Hat: 1 advisoryRed Hat: 1 fixed, 2 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:php:php:*:*:*:*:*:*:*:*before 7.4.24; 8.0.0 to before 8.0.11VulnerablePHP
  • cpe:2.3:a:php:php:*:*:*:*:*:*:*:* Versions before 7.4.24; 8.0.0 to before 8.0.11 Vulnerable ·PHP

Remediation

Red Hat 1 advisory

  • RHSA-2023:2903 Released 2023-05-16 · Red Hat rating Moderate
    php:7.4 security update
    • Red Hat Enterprise Linux AppStream (v. 8) apcu-panel-5.1.18-1.module+el8.3.0+6678+b09f589e.noarch::php:7.4, libzip-1.6.1-1.module+el8.3.0+6678+b09f589e.aarch64::php:7.4, libzip-1.6.1-1.module+el8.3.0+6678+b09f589e.ppc64le::php:7.4 +47

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 8AffectedNo fix yet
Red Hat Software CollectionsAffectedNo fix planned: Will not fix
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2023:2903
Not affected: 4 products
  • Red Hat Enterprise Linux 5
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Software Collections

Timeline

  1. 2026-10-02 Threatist record created from CVE-2017-8923
  2. 2026-10-03 Alias added: GHSA-wrc8-jp87-rq8j

References

Exploit 1

  • TI-2024-04260 Argument Injection in PHP-CGI KEVCVSS 3.1CRITICAL 9.8
  • TI-2019-08259 Underflow in PHP-FPM can lead to RCE KEVCVSS 3.1CRITICAL 9.8
  • TI-2012-01607 sapi/cgi/cgi_main.c in PHP before 5.3.12 and 5.4.x before 5.4.2, when configured as a CGI… KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-78794 PHP remote code execution via stale global state KEVCVSS 4.0CRITICAL 9.2
  • TI-2026-78793 Out-of-memory handling flaw in PHP allows remote code execution KEVCVSS 4.0CRITICAL 9.2
  • TI-2015-00205 Heap-based buffer overflow in the __nss_hostname_digits_dots function in glibc 2.2, and… CVSS 2.0HIGH 10.0
See all 739 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences