Answer in brief
CVE-2026-0300 records a High severity vulnerability in PAN-OS: Unauthenticated user initiated Buffer Overflow Vulnerability in User-ID™ Authentication Portal. The current sources mark it as known exploited. The current feed maps Palo Alto Networks/PAN-OS (generic), Siemens/RUGGEDCOM APE1808 (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. Known-exploitation status makes exposure review time-sensitive. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Palo Alto Networks/PAN-OS (generic), Siemens/RUGGEDCOM APE1808 (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Palo Alto Networks/PAN-OSgeneric | >=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 | 12.1.7, 11.2.12, 11.1.15, 10.2.18-h6 |
| Siemens/RUGGEDCOM APE1808generic | >=0 <* | * |
Published upstream
May 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
May 24, 2026
Added to CISA KEV
May 6, 2026
Evidence: source:kev:kev:kev:recordA 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.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-0300 records a High severity vulnerability in PAN-OS: Unauthenticated user initiated Buffer Overflow Vulnerability in User-ID™ Authentication Portal. The current sources mark it as known exploited. The current feed maps Palo Alto Networks/PAN-OS (generic), Siemens/RUGGEDCOM APE1808 (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. Known-exploitation status makes exposure review time-sensitive. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Palo Alto Networks/PAN-OS (generic), Siemens/RUGGEDCOM APE1808 (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Palo Alto Networks/PAN-OSgeneric | >=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 | 12.1.7, 11.2.12, 11.1.15, 10.2.18-h6 |
| Siemens/RUGGEDCOM APE1808generic | >=0 <* | * |
Published upstream
May 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
May 24, 2026
Added to CISA KEV
May 6, 2026
Evidence: source:kev:kev:kev:recordA 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.
Quoted source text, attributed separately from HOL analysis.