CVEs / CVE-2026-109618
CVE-2026-109618: PHP Memory Corruption Vulnerability
- Known exploited in the CISA KEV catalog since 26 Oct 2026
- critical 9.8 CVSS 3.1 (NVD)
- EPSS 99.9% chance of exploitation in the next 30 days, higher than 99% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
PHP contains an out-of-memory corruption vulnerability that allows for unauthenticated remote code execution.
Description
PHP uses longjmp() for out-of-memory (OOM) errors to exit the current context and abort handling of the request. Some contexts may not properly account for this scenario and leave request memory in an uninitialized state before performing an allocation. The subsequent request cleanup procedure may read or branch on this memory. Multiple OOM strategies can consistently trigger this condition and lead to remote code execution (RCE).
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| PHP Group PHP | from 8.2.*, before 8.2.35 | 8.2.35 |
| PHP Group PHP | from 8.3.*, before 8.3.36 | 8.3.36 |
| PHP Group PHP | from 8.4.*, before 8.4.27 | 8.4.27 |
| PHP Group PHP | from 8.5.*, before 8.5.12 | 8.5.12 |
| Siemens RUGGEDCOM APE1808 | all versions | — |
| Siemens AMIS TS | all versions | — |
| Siemens blueplanet 360 NX3 M6 WM OD IISX | all versions | — |
| Siemens blueplanet 360 NX3 M6 WM OD IISX - S | all versions | — |
| Siemens Energy Engage V2.0SP9 | all versions | — |
| Siemens Energy Engage V3.1SP1 | all versions | — |
| Siemens Spectrum Power 4 | all versions | — |
| Siemens Spectrum Power 7 | all versions | — |
| Siemens Spectrum Power TG | all versions | — |
Exploitation
| In CISA KEV since | 26 Oct 2026 |
|---|---|
| Due date for US federal agencies | 29 Oct 2026 |
| Used in ransomware campaigns | Unknown |
| Required action | Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines. |
Severity
| CVSS 3.1 | 9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HScored by NVD |
|---|---|
| Weakness | CWE-416, CWE-755, CWE-824, CWE-1325 |
On the Stackurity blog
- Linux kernel flaw CVE-2026-46300 joins CISA's exploited list 29 Oct 2026
- CISA adds two PHP remote code execution flaws to its KEV list 28 Oct 2026
References
- CVE-2026-109618 on NVD
- CVE-2026-109618 in the CISA KEV catalog
- https://www.php.net/ (cited by CISA)
- https://www.cisa.gov/news-events/alerts/2026/10/21/critical-vulnerabilities-php-require-immediate-patching (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk (cited by CISA)
- https://github.com/php/php-src/security/advisories/GHSA-w8hw-w9fx-j79w Mitigation, Vendor Advisory
- http://seclists.org/fulldisclosure/2026/Oct/51 Mailing List
- http://www.openwall.com/lists/oss-security/2026/10/21/6 Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2026/10/23/5 Mailing List, Third Party Advisory
- https://arcticwolf.com/resources/blog/php2shell-critical-php-vulnerabilities-enable-unauthenticated-remote-code-execution/ Third Party Advisory
- https://cert-portal.siemens.com/productcert/html/ssa-166980.html
- https://cert-portal.siemens.com/productcert/html/ssa-566435.html
- https://cert-portal.siemens.com/productcert/html/ssa-566512.html Third Party Advisory
- https://php2shell.delftintellab.com Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-109618 US Government Resource
- https://www.wiz.io/blog/php2shell-php-rce Third Party Advisory
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.