CVE-2026-0300

Analyzed
Published: 06 May 2026, 18:57
Last modified:12 May 2026, 12:08

Vulnerability Summary

Overall Risk (default)
high
70/100
CVSS Score
9.8 CRITICAL
v3.1 (nvd)
EPSS Score
6.22% LOW
6% probability +0.94%
KEV
Listed
CISA
1 listing
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

06 May 2026, 18:57
Published
Vulnerability first disclosed
06 May 2026, 00:00
Added to CISA KEV
Palo Alto Networks PAN-OS Out-of-bounds Write Vulnerability
09 May 2026, 00:00
CISA Remediation Due
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.
12 May 2026, 12:08
Last Modified
Vulnerability information updated

Description

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.

CVSS Metrics

  • v4.0•CRITICAL•Score: 9.3CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:N/E:A/AU:Y/R:U/V:C/RE:M/U:Red
  • v4.0•CRITICAL•Score: 9.3CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:N/E:A/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:Y/R:U/V:C/RE:M/U:Red
  • v3.1•CRITICAL•Score: 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 6.22%• Percentile: 91%

Techniques & Countermeasures

  • CWE-787•Out-of-bounds Write

    The product writes data past the end, or before the beginning, of the intended buffer.

Affected Systems

  • palo alto networks•pan-os

    ≥ 12.1.0, < 12.1.7 | ≥ 11.2.0, < 11.2.12 | ≥ 11.1.0, < 11.1.15 | ≥ 10.2.0, < 10.2.18-h6

  • paloaltonetworks•pan-os

    10.2.0 | 10.2.1 | 10.2.2 | 10.2.3 | 10.2.4 | 10.2.5 | 10.2.6 | 10.2.7 | 10.2.7:h1 | 10.2.7:h12 | 10.2.7:h16 | 10.2.7:h19 | 10.2.7:h21 | 10.2.7:h24 | 10.2.7:h3 | 10.2.7:h32 | 10.2.7:h6 | 10.2.7:h8 | 10.2.8 | 10.2.9 | 10.2.10 | 10.2.10:h10 | 10.2.10:h12 | 10.2.10:h14 | 10.2.10:h17 | 10.2.10:h18 | 10.2.10:h2 | 10.2.10:h21 | 10.2.10:h27 | 10.2.10:h3 | 10.2.10:h30 | 10.2.10:h31 | 10.2.10:h4 | 10.2.10:h5 | 10.2.10:h7 | 10.2.10:h9 | 10.2.11 | 10.2.12 | 10.2.13 | 10.2.13:h1 | 10.2.13:h10 | 10.2.13:h16 | 10.2.13:h18 | 10.2.13:h2 | 10.2.13:h3 | 10.2.13:h4 | 10.2.13:h5 | 10.2.13:h7 | 10.2.14 | 10.2.15 | 10.2.16 | 10.2.16:h1 | 10.2.16:h4 | 10.2.16:h6 | 10.2.17 | 10.2.18 | 10.2.18:h1 | 10.2.18:h5 | 11.1.0 | 11.1.1 | 11.1.2 | 11.1.3 | 11.1.4 | 11.1.4:h1 | 11.1.4:h13 | 11.1.4:h15 | 11.1.4:h16 | 11.1.4:h17 | 11.1.4:h18 | 11.1.4:h25 | 11.1.4:h27 | 11.1.4:h32 | 11.1.4:h4 | 11.1.4:h7 | 11.1.4:h9 | 11.1.5 | 11.1.6 | 11.1.6:h1 | 11.1.6:h10 | 11.1.6:h14 | 11.1.6:h17 | 11.1.6:h19 | 11.1.6:h2 | 11.1.6:h20 | 11.1.6:h21 | 11.1.6:h22 | 11.1.6:h23 | 11.1.6:h25 | 11.1.6:h29 | 11.1.6:h3 | 11.1.6:h4 | 11.1.6:h5 | 11.1.6:h6 | 11.1.6:h7 | 11.1.7 | 11.1.7:h1 | 11.1.7:h2 | 11.1.7:h4 | 11.1.8 | 11.1.9 | 11.1.10 | 11.1.10:h1 | 11.1.10:h10 | 11.1.10:h12 | 11.1.10:h21 | 11.1.10:h4 | 11.1.10:h5 | 11.1.10:h7 | 11.1.10:h9 | 11.1.11 | 11.1.12 | 11.1.13 | 11.1.13:h1 | 11.1.13:h2 | 11.1.13:h3 | 11.1.14 | 11.2.0 | 11.2.1 | 11.2.2 | 11.2.3 | 11.2.4 | 11.2.4:h1 | 11.2.4:h10 | 11.2.4:h11 | 11.2.4:h12 | 11.2.4:h14 | 11.2.4:h15 | 11.2.4:h2 | 11.2.4:h4 | 11.2.4:h5 | 11.2.4:h6 | 11.2.4:h7 | 11.2.4:h8 | 11.2.4:h9 | 11.2.5 | 11.2.6 | 11.2.7 | 11.2.7:h1 | 11.2.7:h10 | 11.2.7:h11 | 11.2.7:h12 | 11.2.7:h2 | 11.2.7:h3 | 11.2.7:h4 | 11.2.7:h7 | 11.2.7:h8 | 11.2.8 | 11.2.9 | 11.2.10 | 11.2.10:h1 | 11.2.10:h2 | 11.2.10:h3 | 11.2.10:h4 | 11.2.10:h5 | 11.2.11 | 12.1.2 | 12.1.3 | 12.1.4 | 12.1.4:h2 | 12.1.4:h3 | 12.1.5 | 12.1.6

  • siemens•ruggedcom_ape1808_firmware

    na

References (3)