RCE via OOM corruption (CVE-2026-109618)
Published Last modified Sources: CVE.org, Palo Alto Networks, Ubuntu, CERT-EU, Debian, BSI
- Actively exploited
- Source: VulnCheck KEV (opens in a new tab), ANSSI / CERT-FR How we classify
What is affected, what to do
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 vulnerability is being actively exploited; treat it as a priority. Update PHP to version 8.2.35, PHP to version 8.3.36, PHP to version 8.4.27.
- Affected
- PHP
lt 8.2.0..8.2.35 - PHP
lt 8.3.0..8.3.36 - PHP
lt 8.4.0..8.4.27 - PHP
lt 8.5.0..8.5.12
- PHP
- Fixed in
- PHP
8.2.35 - PHP
8.3.36 - PHP
8.4.27 - PHP
8.5.12
- PHP
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Metrics
9.2
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: Vendor (CNA), CVSS v4
9.2
CVSS v4
Severity Critical on the scale from 0 to 10.
Source: CVE.org, Palo Alto Networks, Ubuntu, CERT-EU, Debian, BSI
—
EPSS score
No value is available for this vulnerability.
Show all metrics
- Severity
- Critical
Priority (0–325)
The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?
Read in glossary- 76.00 Methodology
Exploit maturity
An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.
Read in glossary- actively exploitedSource: VulnCheck KEV (opens in a new tab), ANSSI / CERT-FR How we classify
XIEM Effective CVSS
XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.
Read in glossary- 9.2 Methodology
CVSS v4
CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.
Read in glossary- 9.2
KEV status
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- —
- Published
CWE
CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.
Read in glossary- CWE-416, CWE-755, CWE-824, CWE-1325, CWE-1419
Detection rules
No NEOSEC detection rule is available for this vulnerability yet.
Classification under NIS2 and CRA
Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.
NIS2
NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.
Read in glossary- Actively exploited: treat the vulnerability as a priority in vulnerability handling under Art. 21(2)(e) NIS2. If it is exploited in your environment, check the reporting obligation under Art. 23 (early warning within 24 hours).
CRA
The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.
Read in glossary- Since 11.09.2026, manufacturers of affected products with digital elements must report actively exploited vulnerabilities under Art. 14 CRA, with an early warning within 24 hours via ENISA's single reporting platform.
ISO/IEC 27001
ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.
Read in glossary- Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.
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).
Source: cvelistv5, paloalto_rss, Ubuntu Security Notices, certeu_advisory, Debian Security Advisories, CVE.org (MITRE), BSI WID Portal, BSI CSAF
Affected products
The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| PHP Group | PHP |
|
|
Affected operating systems
| Family | Vendor | Product | Version |
|---|---|---|---|
| Linux | ubuntu | php5 | trusty |
| Linux | ubuntu | php7.0 | xenial |
| Linux | ubuntu | php7.2 | bionic |
| Linux | ubuntu | php7.4 | focal |
| Linux | ubuntu | php8.1 | jammy |
| Linux | ubuntu | php8.3 | noble |
| Linux | debian | php8.4 | trixie |
| Linux | ubuntu | php8.5 | resolute |
| Linux | ubuntu | php8.5 | stonking |
Weakness classes (CWE)
CWE-416Use After Free
Variant
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
Entry at MITRE CWE-416CWE-755Improper Handling of Exceptional Conditions
Class
The product does not handle or incorrectly handles an exceptional condition.
Entry at MITRE CWE-755CWE-824Access of Uninitialized Pointer
Base
The product accesses or uses a pointer that has not been initialized.
Entry at MITRE CWE-824CWE-1325Improperly Controlled Sequential Memory Allocation
Base
The product manages a group of objects or resources and performs a separate memory allocation for each object, but it does not properly limit the total amount of memory that is consumed by all of the combined objects.
Entry at MITRE CWE-1325CWE-1419Incorrect Initialization of Resource
Class
The product attempts to initialize a resource but does not correctly do so, which might leave the resource in an unexpected, incorrect, or insecure state when it is accessed.
Entry at MITRE CWE-1419
Public exploit references
Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.
| Source | Reference | Maturity | Published |
|---|---|---|---|
| ANSSI / CERT-FRLicence Ouverte 2.0, as of | CERTFR-2026-ALE-014 – [Màj] Multiples vulnérabilités dans PHP (opens in a new tab)cert.cyber.gouv.fr | actively exploited |
References & sources
- github.comphp/php-src/security/advisories/GHSA-w8hw-w9fx-j79wVendor advisory
- cert.atCERT.at: Kritische Sicherheitslücken in PHP - Updates verfügbarcert-at
- cert.cyber.gouv.frANSSI / CERT-FR: CERTFR-2026-ALE-014 – [Màj] Multiples vulnérabilités dans PHPcert-fr
- wiz.ioblog/php2shell-php-rceThird-party advisory
- openwall.comlists/oss-security/2026/10/21/6
Reanalysis & status changes
Chronological NVD audit events for this CVE — reanalyses, CVSS updates, CPE diffs.
CVE Modified134c704f-9b21-4f2e-91b3-4a467353bcc0
- Reference: after https://www.wiz.io/blog/php2shell-php-rce
- SSVC: after {"id":"CVE-2026-109618","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technical…
New CVE Receivedsecurity@php.net
- Description: after 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).
- CVSS V4.0: after AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- CWE: after CWE-824
- CWE: after CWE-416
Linked advisories
- Two critical PHP flaws put the web on alert as emergency patches arriveCSO Online
- PHP2Shell Patches Land as First Exploitation Attempts Hit SensorsSecurityWeek
- PHP ships emergency patches for critical PHP2Shell flawsBleepingComputer
- NCSC-2026-0443 [1.00] [H/H] Kwetsbaarheden verholpen in PHPNCSC-NL
- Critical PHP Vulnerability (CVE-2026-109618, CVE-2026-109619) [infocon yellow], (Wed, Oct 21st)SANS ISC Diary
- PHP2Shell: Mass Exploitation Looms for Leaked Critical PHP FlawsSecurityWeek
- PHP core RCE vulnerability patches (CVE-2026-109618 and CVE-2026-109619)Fortinet PSIRT
- Vulnerabilities in PHP Affecting Cisco Products: October 2026Cisco PSIRT
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<a href="https://intel.neosec.eu/en/cve/CVE-2026-109618"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-109618.svg?lang=en" alt="CVE-2026-109618 – NEOSEC Intel" height="20"></a>