How severe is CVE-2021-3056?

CVE-2021-3056 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-3056 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3056?

CVE-2021-3056 primarily affects Paloaltonetworks Pan-os. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-3056?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-3056 published?

CVE-2021-3056 was published on 2021-11-10 and last updated on 2026-06-17.

CVE-2021-3056

CVE-2021-3056 is a high-severity vulnerability in Paloaltonetworks Pan-os with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 8.5
EPSS exploit prediction: 1% (71st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Paloaltonetworks Pan-os
Published: 2021-11-10
Last modified: 2026-06-17

Description

A memory corruption vulnerability in Palo Alto Networks PAN-OS GlobalProtect Clientless VPN enables an authenticated attacker to execute arbitrary code with root user privileges during SAML authentication. This issue impacts: PAN-OS 8.1 versions earlier than PAN-OS 8.1.20; PAN-OS 9.0 versions earlier than PAN-OS 9.0.14; PAN-OS 9.1 versions earlier than PAN-OS 9.1.9; PAN-OS 10.0 versions earlier than PAN-OS 10.0.1. Prisma Access customers with Prisma Access 2.1 Preferred firewalls are impacted by this issue.

Frequently asked questions

What is CVE-2021-3056?: A memory corruption vulnerability in Palo Alto Networks PAN-OS GlobalProtect Clientless VPN enables an authenticated attacker to execute arbitrary code with root user privileges during SAML authentication. This issue impacts: PAN-OS 8.1 versions earlier than PAN-OS 8.1.20; PAN-OS 9.0 versions earlier than PAN-OS 9.0.14; PAN-OS 9.1 versions earlier than PAN-OS 9.1.9; PAN-OS 10.0 versions earlier than PAN-OS 10.0.1. Prisma Access customers with Prisma Access 2.1 Preferred firewalls are impacted by this issue.
How severe is CVE-2021-3056?: CVE-2021-3056 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-3056 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3056?: CVE-2021-3056 primarily affects Paloaltonetworks Pan-os. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-3056?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-3056 published?: CVE-2021-3056 was published on 2021-11-10 and last updated on 2026-06-17.

References

https://security.paloaltonetworks.com/CVE-2021-3056

Affected products (2)

cpe:2.3:o:paloaltonetworks:pan-os:*:*:*:*:*:*:*:*
cpe:2.3:o:paloaltonetworks:pan-os:10.0.0:*:*:*:*:*:*:*

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