CVE-2026-0300
criticalpriority · act · 90OT risk · criticalKEV · exploitedEPSS 0.317 · 98 %ileexploit · PoCDEEUNLRUUSadded 2026-05-06remediate by 2026-05-09
required action Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. Until the vendor releases an official fix, the following workaround should be implemented: - Restrict User-ID Authentication Portal access to only trusted zones. - Disable User-ID Authentication Portal if not required. 5/13/2026: Palo Alto has released a variety of patches. If these are relevant to your environment, please apply the designated patch.
EPSS · scored 2026-10-24
Palo Alto Networks PAN-OS Out-of-bounds Write Vulnerability
A buffer overflow vulnerability in the User-ID™ Authentication Portal (aka Captive Portal) service of Palo Alto Networks PAN-OS software allows an unauthenticated attacker to execute arbitrary code with root privileges on the PA-Series and VM-Series firewalls by sending specially crafted packets. The risk of this issue is greatly reduced if you secure access to the User-ID™ Authentication Portal per the best practice guidelines https://knowledgebase.paloaltonetworks.com/KCSArticleDetail by restricting access to only trusted internal IP addresses. Prisma Access, Cloud NGFW and Panorama appliances are not impacted by this vulnerability.
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
A vendor fix is available.
- FixedRUGGEDCOM APE1808siemens_psirt
Upgrade Palo Alto Networks Virtual NGFW V11.2.10-h6. Contact customer support to receive patch and update information
- FixedRUGGEDCOM APE1808cisa_csaf_ot
Contact customer support to receive patch and update information
- MitigationRUGGEDCOM APE1808siemens_psirt
Disable Response Pages in the Interface Management Profile attached to every L3 interface in any zone where untrusted/internet traffic can ingress. Keep Response Pages enabled only on interfaces in trust/internal zones where legitimate users' browsers ingress
- MitigationRUGGEDCOM APE1808cisa_csaf_ot
Disable Response Pages in the Interface Management Profile attached to every L3 interface in any zone where untrusted/internet traffic can ingress. Keep Response Pages enabled only on interfaces in trust/internal zones where legitimate users' browsers ingress
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 7.3–10
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
exploits (10)
Public proof-of-concept and weaponised exploit code.
- 0xBlackash/CVE-2026-0300CVE-2026-0300PoC · poc_in_github
- lu4m575/CVE-2026-0300CVE-2026-0300 PAN-OS 12.1, 11.2, 11.1, 10.2PoC · poc_in_github
- mr-r3b00t/CVE-2026-0300a honeypot for CVE-2026-0300PoC · poc_in_github
- p3Nt3st3r-sTAr/CVE-2026-0300-POCp3Nt3st3r-sTAr/CVE-2026-0300-POCPoC · poc_in_github
affected products (112)
Products and version ranges known to be affected.
advisories (4)
Vendor and ecosystem advisories describing this.
- NCSC-2026-0132Kwetsbaarheid verholpen in Palo Alto Networks PAN-OSNL2026-05-06csaf · ncsc_nlNL
Palo Alto Networks heeft een kwetsbaarheid verholpen in PAN-OS, specifiek in de User-ID Authentication Portal component van PA-Series en VM-Series firewalls.
- SSA-967325SSA-967325: Multiple Vulnerabilities in Palo Alto Networks PAN-OS before V11.2.10-h7 on RUGGEDCOM APE1808 Devices2026-05-12csaf · siemens_psirtDE
Palo Alto Networks has published [1] information on vulnerabilities in PAN-OS. This advisory lists the related Siemens Industrial products affected by these vulnerabilities. Siemens has released a new version for RUGGEDCOM APE1808 and recommends to update to the latest version. Customers are advised to consult and implement the workarounds provided in Palo Alto Networks' upstream security notifications. [1] https://security.paloaltonetworks.com/
- WID-SEC-W-2026-1366Palo Alto Networks PAN-OS: Schwachstelle ermöglicht Ausführen von beliebigem Programmcode mit AdministratorrechtenDeutsch2026-05-05csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Palo Alto Networks PAN-OS ausnutzen, um beliebigen Programmcode mit Administratorrechten auszuführen.
- ICSA-26-139-02Siemens RUGGEDCOM APE1808 Devices2026-05-12icsa · cisa_csaf_otUS
Palo Alto Networks has published [1] information on vulnerabilities in PAN-OS. This advisory lists the related Siemens Industrial products affected by these vulnerabilities. Siemens is preparing fix versions and recommends countermeasures for products where fixes are not, or not yet available. Customers are advised to consult and implement the workarounds provided in Palo Alto Networks' upstream security notifications. [1] https://security.paloaltonetworks.com/
also known as (4)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (6)
External citations — patches, advisories, analysis.
- https://nvd.nist.gov/vuln/detail/CVE-2026-0300cnnvd
- https://security.paloaltonetworks.com/CVE-2026-0300Patchcnnvd
- https://security.paloaltonetworks.com/CVE-2026-0300enisa_euvd
- https://cert-portal.siemens.com/productcert/html/ssa-967325.htmlThird Party Advisorynvd
- https://security.paloaltonetworks.com/CVE-2026-0300MitigationVendor Advisorynvd
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-0300US Government Resourcenvd
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