CVE Intelligence
CISA KEV Critical Authentication

CVE-2026-0257 — Palo Alto Networks PAN-OS Authentication Bypass Vulnerability

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.

Published May 13, 2026 · Updated Oct 15, 2026 · Sources: CISA Known Exploited Vulnerabilities, NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: palo_alto

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

CISA KEV · May 29, 2026 R used by ransomware (CISA) Detection templates (Nuclei) · 1Proofs of concept on GitHub · 7
How the score was calculated
  • Confirmed exploitation (CISA KEV)+35
  • Used in ransomware campaigns (CISA)+10
  • Public exploit/PoC (nuclei, github)+10
  • EPSS 96.9% (30-day exploitation probability)+15
  • Technical severity (critical)+10

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Confirmed
CISA KEV, listed May 29, 2026
EPSS FIRST
96.9%
ahead of 100% of scored CVEs · Oct 14, 2026
Affects
Palo Alto Networks
PAN-OS and 2 more
CVSS base
9.1
Critical · 4 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
Active
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

CISA required action CISA

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

US federal deadline: Jun 1, 2026 — passed 136 day(s) ago

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Palo Alto Networks PAN-OS, Palo Alto Networks Prisma Access, Siemens Ruggedcom Ape1808 Firmware).
  2. Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
  3. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  4. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  5. EPSS ahead of 100% of scored CVEs: prioritize it in the patch queue.
  6. Search available logs for exploit probes matching the vulnerability class (authentication), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Palo Alto Networks PAN-OS version 12.1.2version 11.2.7-h8version 11.2.8version 11.2.9version 11.2.10version 11.2.10-h1version 11.2.10-h2version 11.2.10-h3
and 152 more version 11.2.10-h4version 11.2.10-h5version 11.2.10-h6version 11.2.11version 11.2.4-h10version 12.1.3version 12.1.4version 12.1.4-h2version 12.1.4-h3version 12.1.4-h5version 12.1.5version 12.1.6version 11.2.7-h4version 11.2.4-h1version 11.2.4-h11version 11.2.4-h12version 11.2.4-h14version 11.2.4-h15version 11.2.4-h2version 11.2.4-h4version 11.2.4-h5version 11.2.4-h6version 11.2.4-h7version 11.2.4-h8version 11.2.4-h9version 11.2.5version 11.2.6version 11.2.7version 11.2.7-h1version 11.2.7-h10version 11.2.7-h11version 11.2.7-h12version 11.2.7-h13version 11.2.7-h2version 11.2.7-h3version 11.2.7-h7< 10.2.7version 10.2.7version 10.2.7-h1version 10.2.7-h12version 10.2.7-h16version 10.2.7-h18version 10.2.7-h19version 10.2.7-h21version 10.2.7-h24version 10.2.7-h3version 10.2.7-h32version 10.2.7-h6version 10.2.7-h8version 10.2.8version 10.2.9version 10.2.10version 10.2.10-h10version 10.2.10-h12version 10.2.10-h14version 10.2.10-h17version 10.2.10-h18version 10.2.10-h2version 10.2.10-h21version 10.2.10-h27version 10.2.10-h3version 10.2.10-h30version 10.2.10-h31version 10.2.10-h4version 10.2.10-h5version 10.2.10-h7version 10.2.10-h9version 10.2.11version 10.2.12version 10.2.13version 10.2.13-h1version 10.2.13-h10version 10.2.13-h16version 10.2.13-h18version 10.2.13-h2version 10.2.13-h3version 10.2.13-h4version 10.2.13-h5version 10.2.13-h7version 10.2.14version 10.2.15version 10.2.16version 10.2.16-h1version 10.2.16-h4version 10.2.16-h6version 10.2.17version 10.2.18version 10.2.18-h1version 10.2.18-h5version 11.1.0version 11.1.1version 11.1.2version 11.1.3version 11.1.4version 11.1.4-h1version 11.1.4-h13version 11.1.4-h15version 11.1.4-h16version 11.1.4-h17version 11.1.4-h18version 11.1.4-h25version 11.1.4-h27version 11.1.4-h32version 11.1.4-h4version 11.1.4-h7version 11.1.4-h9version 11.1.5version 11.1.6version 11.1.6-h1version 11.1.6-h10version 11.1.6-h14version 11.1.6-h17version 11.1.6-h19version 11.1.6-h2version 11.1.6-h20version 11.1.6-h21version 11.1.6-h22version 11.1.6-h23version 11.1.6-h25version 11.1.6-h29version 11.1.6-h3version 11.1.6-h4version 11.1.6-h5version 11.1.6-h6version 11.1.6-h7version 11.1.7version 11.1.7-h1version 11.1.7-h2version 11.1.7-h4version 11.1.8version 11.1.9version 11.1.10version 11.1.10-h1version 11.1.10-h10version 11.1.10-h12version 11.1.10-h21version 11.1.10-h4version 11.1.10-h5version 11.1.10-h7version 11.1.10-h9version 11.1.11version 11.1.12version 11.1.13version 11.1.13-h1version 11.1.13-h2version 11.1.13-h3version 11.1.14version 11.2.0version 11.2.1version 11.2.2version 11.2.3version 11.2.4
Vulnerable NIST National Vulnerability Database
Palo Alto Networks PAN-OS ≥ 12.1.0 and < 12.1.7, 12.1.4-h6≥ 11.2.0 and < 11.2.12, 11.2.10-h7, 11.2.7-h14, 11.2.4-h17≥ 11.1.0 and < 11.1.15, 11.1.13-h5, 11.1.10-h25, 11.1.7-h6, 11.1.6-h32, 11.1.4-h33≥ 10.2.0 and < 10.2.18-h6, 10.2.16-h7, 10.2.13-h21, 10.2.10-h36, 10.2.7-h34 Vulnerable CVE Program (cve.org) e CISA ADP
Palo Alto Networks Prisma Access versions not specified by the source Vulnerable NIST National Vulnerability Database
Palo Alto Networks Prisma Access ≥ 10.2.0 and < 10.2.10-h36≥ 11.2.0 and < 11.2.7-h13 Vulnerable CVE Program (cve.org) e CISA ADP
Siemens Ruggedcom Ape1808 Firmware versions not specified by the source Vulnerable NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
7.8 CVSS 4.0 High — — psirt@paloaltonetworks.com via NIST National Vulnerability Database
7.8 CVSS 4.0 High — — palo_alto via CVE Program (cve.org) e CISA ADP
9.1 CVSS 3.1 Critical 3.9 5.2 nvd@nist.gov via NIST National Vulnerability Database
9.1 CVSS 3.1 Critical — — GitHub, Inc. via GitHub Security Advisories
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-565 · Reliance on Cookies without Validation and Integrity Checking

Other CVEs with this weakness →

CISA KEV details CISA

CISA lists a CVE once it has evidence of exploitation against real targets.

Listed
May 29, 2026
Federal deadline
Jun 1, 2026
passed 136 day(s) ago
Ransomware use
Known

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.

Public exploits, PoCs and detection templates

Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.

Detection templates (Nuclei)
Proofs of concept on GitHub

Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.

EPSS over time FIRST

Oct 12, 2026 → Oct 14, 2026 · 3 reading(s) · max 96.90%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Review authentication logs: logins without MFA, anomalous sessions and recently created accounts.
  • Hunt retroactively in logs from before May 29, 2026 (KEV listing): exploitation may have started earlier.
web/proxy/WAF logsnetwork IDS/IPSauthentication logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products removed · 6
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Affected products added · palo alto networks/pan-os, palo alto networks/prisma access
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Affected products added · palo alto networks/pan-os, palo alto networks/prisma access
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • Affected products added · paloaltonetworks/pan-os, paloaltonetworks/prisma access, siemens/ruggedcom ape1808 firmware
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVSS changed · 9.1
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Analyzed
    Oct 13, 2026 · NIST National Vulnerability Database
  • Added to CISA KEV (detected)
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • Record created in this database
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • Added to CISA KEV catalog
    May 28, 2026 · CISA
  • CVE published
    May 13, 2026 · palo_alto

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 13, 2026 – Oct 13, 2026
  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

5 on the record

Elsewhere on this site

Palo Alto Networks
every CVE for this vendor
2026-05
what else CISA listed that month
Authentication
same class
CWE-565
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-0320 PAN-OS: Authenticated Admin Command Injection Vulnerability 20h
  • CVE-2026-0318 PAN-OS: Denial of Service (DoS) on Panorama 20h
  • CVE-2026-0319 PAN-OS: Improper Input Handling Vulnerability 20h
  • CVE-2026-0316 PAN-OS: Stored Cross-Site Scripting (XSS) Vulnerability 20h
  • CVE-2026-0317 PAN-OS: Denial of Service Vulnerability 20h
  • CVE-2026-0321 PAN-OS: Denial of Service (DoS) Vulnerabilities in Network Services 21h

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No fixed version, patch or mitigation documented.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-0257 is "Palo Alto Networks PAN-OS Authentication Bypass Vulnerability", rated Critical. It affects PAN-OS (Palo Alto Networks); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 9.1 describes technical severity. EPSS 96.90% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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