PAN-OS 9.1
9.1
Os Release
· PAN-OS Series
Is PAN-OS 9.1 still maintained?
No. Palo Alto no longer maintains PAN-OS 9.1; support ended 2024-06-30. It receives no fixes of any kind, including security patches. Devices running it are unpatched against any newer vulnerability — plan an upgrade to a maintained release. See Palo Alto's lifecycle bulletin.
When do security fixes for PAN-OS 9.1 stop?
Engineering fixes for PAN-OS 9.1 — including security patches — stop on 2024-06-30. After that date, a device on this release cannot be patched against newly disclosed vulnerabilities without upgrading, which is the point that matters for KEV exposure and compliance.
What should I upgrade PAN-OS 9.1 to?
Upgrade to a currently maintained Palo Alto release. Check the release-train table on the vendor page for the nearest supported version.
What known-exploited CVEs apply to the PAN-OS 9.1 past end of support?
4 CVEs in CISA's Known Exploited Vulnerabilities catalog affect Palo Alto PAN-OS. Because PAN-OS 9.1 is past end of engineering, it will not receive fixes for them — a device left on this release is exploitable with no patch available. Upgrade to a maintained release. See the Known Exploited Vulnerabilities table below for the full list.
Known Exploited Vulnerabilities
This device is past Palo Alto's security-support date. 4 CVEs in CISA's Known Exploited Vulnerabilities catalog apply to the platform it runs. Palo Alto is not issuing patches for this model. Isolate, compensate, or refresh.
| CVE | KEV added | Vulnerability | Flags |
|---|---|---|---|
CVE-2026-0257
|
Palo Alto Networks PAN-OS Authentication Bypass Vulnerability | ||
CVE-2026-0300
|
Palo Alto Networks PAN-OS Out-of-bounds Write Vulnerability | ||
CVE-2022-0028
|
Palo Alto Networks PAN-OS Reflected Amplification Denial-of-Service Vulnerability | ||
CVE-2020-2021
|
Palo Alto Networks PAN-OS Authentication Bypass Vulnerability | Ransomware |
Source: CISA Known Exploited Vulnerabilities catalog. The Ransomware flag reflects CISA's own knownRansomwareCampaignUse field, set when the CVE has been observed in ransomware campaigns per their threat intel. It's not a property of the vulnerability description itself.
Correlation is at the platform level, not per-OS-version. Not exhaustive: KEV only lists actively-exploited CVEs and many relevant unexploited vulnerabilities are not here. Verify against vendor security advisories (PSIRT, JSA, PAN-SA) and NVD before acting. See compensating controls if refresh isn't immediate.
PAN-OS 9.1 Release Lifecycle
PAN-OS 9.1 is a Palo Alto PAN-OS software release. Releases are maintained on a fixed schedule: Palo Alto ships fixes and security patches until the release reaches end of engineering, after which a device must be upgraded to a maintained release to stay patchable. The dates below are milestones for the software train, not for any specific appliance — hardware running this release has its own separate lifecycle. This product has reached end of life as of , meaning Palo Alto no longer provides technical support, software updates, or hardware replacement for this product. Organizations still running the PAN-OS 9.1 should plan a migration .
Lifecycle Milestones
| Lifecycle notice published | 6y 7mo ago | |
|---|---|---|
| End of software maintenance | 2y 1mo ago | |
| End of security vulnerability support | 2y 1mo ago | |
| Last date of support | 2y 1mo ago |