PHP Stale Internal Request-State
CVE-2026-109619 is a high-severity use after free vulnerability in PHP from PHP Group, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 8.2.35, 8.3.36, 8.4.27 as the first without the flaw, so updating PHP to one of those releases or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on October 26, 2026, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update PHP to 8.2.35 or 8.3.36 or 8.4.27 or 8.5.12, whichever matches your release line, or a later version.
- Update Local Monitoring bt-monitoring-vm to V20261103 or a later version.
- CISA's 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.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| PHP Group | PHP | 8.2.* up to, but not including, 8.2.35; 8.3.* up to, but not including, 8.3.36; 8.4.* up to, but not including, 8.4.27; 8.5.* up to, but not including, 8.5.12 | 8.2.35, 8.3.36, 8.4.27, 8.5.12 |
| Siemens | AMIS TS | all versions | Not stated |
| Siemens | AX4 | Not specified in the record | Not stated |
| Siemens | blueplanet 360 NX3 M6 WM OD IISX | all versions | Not stated |
| Siemens | blueplanet 360 NX3 M6 WM OD IISX - S | all versions | Not stated |
| Siemens | Building X | Not specified in the record | Not stated |
| Siemens | CADRA | Not specified in the record | Not stated |
| Siemens | Call stations | Not specified in the record | Not stated |
| Siemens | Capital | Not specified in the record | Not stated |
| Siemens | Chargesight | Not specified in the record | Not stated |
| Siemens | Climatix Cloud IC | Not specified in the record | Not stated |
| Siemens | Climatix Devices | Not specified in the record | Not stated |
| Siemens | Connect Insights | Not specified in the record | Not stated |
| Siemens | Connect X200 | Not specified in the record | Not stated |
| Siemens | Connect X300 | Not specified in the record | Not stated |
| Siemens | Connect X500 | Not specified in the record | Not stated |
| Siemens | cRSP | Not specified in the record | Not stated |
| Siemens | Depotfinity | Not specified in the record | Not stated |
| Siemens | Designcenter | Not specified in the record | Not stated |
| Siemens | Designcenter X | Not specified in the record | Not stated |
| Siemens | Designcenter X Essentials | Not specified in the record | Not stated |
| Siemens | Desigo CC | Not specified in the record | Not stated |
| Siemens | Desigo DXR2 | Not specified in the record | Not stated |
| Siemens | Desigo DXR3 | Not specified in the record | Not stated |
| Siemens | Desigo Optic | Not specified in the record | Not stated |
Version data comes from the organisation that assigned the CVE; 35 further products are omitted here. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 9.2 | Critical | CNA (php.net) |
| CVSS 3.1 | 8.1 | High | NVD |
Official description
PHP has various global state that temporarily points into request memory. In some scenarios, global state may not be correctly reset, or may be repopulated after being reset. The global state may then refer to request memory even after it has been freed. Subsequent requests may read or branch on this stale state before it is fully initialized. Multiple strategies can trigger this condition and produce remote code execution (RCE).
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
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.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- openwall.com/lists/oss-security/2026/10/21/16Mailing List, Third Party Advisory
- openwall.com/lists/oss-security/2026/10/21/17Mailing List, Third Party Advisory
- openwall.com/lists/oss-security/2026/10/21/23Mailing List, Third Party Advisory
- openwall.com/lists/oss-security/2026/10/21/7Mailing List, Third Party Advisory
- openwall.com/lists/oss-security/2026/10/22/14Mailing List, Third Party Advisory
- openwall.com/lists/oss-security/2026/10/22/15Mailing List, Third Party Advisory
- openwall.com/lists/oss-security/2026/10/22/16Mailing List, Third Party Advisory
- openwall.com/lists/oss-security/2026/10/22/19Mailing List, Third Party Advisory
- openwall.com/lists/oss-security/2026/10/22/2Mailing List, Third Party Advisory
- openwall.com/lists/oss-security/2026/10/22/20Mailing List, Third Party Advisory
- openwall.com/lists/oss-security/2026/10/23/4Mailing List, Third Party Advisory
- arcticwolf.com/resources/blog/php2shell-critical-php-vulnerabilities-enable-unauthenticated-remote-code-execu…Third Party Advisory
- cert-portal.siemens.com/productcert/html/ssa-166980.htmlThird Party Advisory
- cert-portal.siemens.com/productcert/html/ssa-566435.htmlThird Party Advisory
- cert-portal.siemens.com/productcert/html/ssa-566512.htmlThird Party Advisory
Our coverage
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