What products are affected by CVE-2026-0257?

CVE-2026-0257 affects Palo Alto Networks PAN-OS. Refer to the vendor advisory and NVD record for affected versions.

Is there a public exploit for CVE-2026-0257?

Yes. Public exploit code or proof-of-concept has been identified for CVE-2026-0257. This lowers the barrier for exploitation and increases the urgency of patching. Organizations should prioritize remediation immediately.

What is the EPSS score for CVE-2026-0257?

CVE-2026-0257 has an EPSS score of 86.7%, placing it in the 100th percentile. This means it has a 86.7% probability of being exploited in the next 30 days, higher than 100% of all known vulnerabilities. EPSS (Exploit Prediction Scoring System) is maintained by FIRST and uses real-world threat data to estimate exploitation likelihood.

Actively Exploited, CISA KEV

CVE-2026-0257: Palo Alto Networks PAN-OS Critical Vulnerability

Severity: Critical | CVSS 3.1: 9.1 | Published: 2026-05-13 | KEV Added: 2026-05-29

What is CVE-2026-0257?

Authentication bypass vulnerabilities in the GlobalProtect portal and gateway of Palo Alto Networks PAN-OS® software allows the attacker to bypass security restrictions and establish an unauthorized VPN connection. Panorama and Cloud NGFW are not impacted by these issues.

Technical Analysis

Weakness Classification

This vulnerability is classified as CWE-565.

Attack Vector Breakdown

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: None

Impact Analysis

This vulnerability is exploitable over the network, meaning any system reachable via the internet or internal network is potentially at risk without physical access. The attack complexity is low, requires no special privileges, and needs no user interaction, making it straightforward to exploit at scale. Successful exploitation can result in full confidentiality breach (complete data disclosure), complete integrity compromise (data modification or code execution).

Exploitation Probability (EPSS): 86.7% chance of exploitation in the next 30 days (100th percentile). This places the vulnerability in the highest risk tier, immediate action is critical.

Exploit Availability

Public exploit code or proof-of-concept is available for CVE-2026-0257. This significantly increases the risk of exploitation, as attackers can use or adapt existing exploit code rather than developing their own. A public exploit reference has been identified. Organizations should treat this as an urgent patching priority.

Is CVE-2026-0257 being exploited?

Yes. CVE-2026-0257 is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, restricted to CVEs with confirmed active exploitation in the wild. CISA added this vulnerability on 2026-05-29. Inclusion in KEV triggers the patching mandate under BOD 22-01 for U.S. federal civilian agencies, with a remediation deadline of 2026-06-01. Additionally, public exploit code is available, which lowers the barrier for attackers.

How to fix CVE-2026-0257

Upgrade PAN-OS to the fixed version listed in the Palo Alto Networks Security Advisory. Use the PAN-OS software update process through the management interface or CLI. If immediate upgrade is not possible, apply Threat Prevention signatures and restrict management interface access as described in the advisory. Check the Palo Alto Networks Security Advisories page for the specific patch or update. CISA's Known Exploited Vulnerabilities catalog requires U.S. federal agencies to remediate this vulnerability by the due date shown below under Binding Operational Directive 22-01. Private organizations should treat KEV entries as priority-one patches because active exploitation has been confirmed in the wild.

Related Vulnerabilities

Other actively exploited vulnerabilities affecting PAN-OS or sharing the same weakness (CWE-565):

CVE-2026-0300 (Critical 9.8) [same product], A buffer overflow vulnerability in the User-ID™ Authentication Portal (aka…

Frequently asked questions

Is CVE-2026-0257 critical?

CVE-2026-0257 has a CVSS 3.1 base score of 9.1, Critical severity. It should be treated as a priority patch, especially given the active exploitation confirmed by CISA. The availability of public exploit code further increases the urgency.

Is CVE-2026-0257 being actively exploited?

Yes, CISA added CVE-2026-0257 to the Known Exploited Vulnerabilities catalog on 2026-05-29. Inclusion in KEV means CISA has confirmed in-the-wild exploitation. Public exploit code has also been identified, making exploitation accessible to a broader range of threat actors.

How do I patch CVE-2026-0257?

Apply the security update from Palo Alto Networks for PAN-OS. Federal agencies must remediate by 2026-06-01 under BOD 22-01. Refer to the Palo Alto Networks Security Advisories for the official patch.

What type of vulnerability is CVE-2026-0257?

CVE-2026-0257 is classified under CWE-565.

What is the CVSS score for CVE-2026-0257?

CVE-2026-0257 has a CVSS 3.1 base score of 9.1, classifying it as Critical severity. The attack vector is Network, attack complexity is Low, and no privileges are required.