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NVD / CVE Program· CNA palo_alto

CVE-2026-0300: PAN-OS: Unauthenticated user initiated Buffer Overflow Vulnerability in User-ID™ Authentication Portal

Noroxi assessment

Priority: Now (action score 80/100)

  • CISA has confirmed exploitation in the wild (May 6, 2026). Remediation deadline for US federal agencies: May 9, 2026.
  • Probability of exploitation in the next 30 days: 41.7% (FIRST EPSS); higher than 98.6% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: Palo Alto Networks PAN-OS 10.2.10-h36, 10.2.13-h21, 10.2.16-h7.
  • Mentioned 2 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Patch today or shut off access. Upgrade to Palo Alto Networks PAN-OS 10.2.10-h36, 10.2.13-h21, 10.2.16-h7 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS

A 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.

CriticalCVSS 9.3 · v4.0KEVWeaponized Fix available
Published
May 6, 2026
Updated
Oct 26, 2026
EPSS
41.7% · 98th percentile

Report tools

JSON

Action score

80

Now

Patch today or shut off access.

CVSS
37 / 40 · 9.3 / 10
CISA KEV
30 / 30 · Listed
EPSS
13 / 30 · 41.7%

CISA SSVC decision

Exploitation
active
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · palo_alto
9.3
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:N/E:A/AU:Y/R:U/V:C/RE:M/U:Red

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on May 6, 2026. That signals real attacks, not theory.

Remediation deadline for US federal agencies: May 9, 2026.

Get told when this record changes

  • In CISA KEV: exploitation in the wild confirmed
  • Weaponized exploit exists
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-0300

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

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Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
paloaltonetworkspan-os
paloaltonetworkspa-1410
paloaltonetworkspa-1420
paloaltonetworkspa-3410
paloaltonetworkspa-3420
paloaltonetworkspa-3430
paloaltonetworkspa-3440
paloaltonetworkspa-410
paloaltonetworkspa-410r
paloaltonetworkspa-410r-5g
paloaltonetworkspa-415
paloaltonetworkspa-415-5g

and 38 more

Using pan-os? Add it to your stack and be the first to know about CVEs like this one. (Firewall)

Watch new CVEs for pan-os

When you'll hear from us

  • when a new CVE affecting this product is published
  • when a record in your stack enters KEV or gets exploit code

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every Monday

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • paloaltonetworks pan-os10.2.0
  • paloaltonetworks pan-os10.2.1
  • paloaltonetworks pan-os10.2.10
  • paloaltonetworks pan-os10.2.11
  • paloaltonetworks pan-os10.2.12
  • paloaltonetworks pan-os10.2.13
  • paloaltonetworks pan-os10.2.14
  • paloaltonetworks pan-os10.2.15
  • paloaltonetworks pan-os10.2.16
  • paloaltonetworks pan-os10.2.17
  • paloaltonetworks pan-os10.2.18
  • paloaltonetworks pan-os10.2.2
  • paloaltonetworks pan-os10.2.3
  • paloaltonetworks pan-os10.2.4
  • paloaltonetworks pan-os10.2.5
  • paloaltonetworks pan-os10.2.6
  • paloaltonetworks pan-os10.2.7
  • paloaltonetworks pan-os10.2.8
  • paloaltonetworks pan-os10.2.9
  • paloaltonetworks pan-os11.1.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (palo_alto). Independent of NVD's CPE analysis and usually ahead of it.

  • Palo Alto Networks Cloud NGFW

    • Allnot affected

  • Palo Alto Networks PAN-OS

    • 12.1.0 and later · before 12.1.7affectedfixed in 12.1.7, 12.1.4-h5
    • 11.2.0 and later · before 11.2.12affectedfixed in 11.2.12, 11.2.10-h6, 11.2.7-h13, 11.2.4-h17
    • 11.1.0 and later · before 11.1.15affectedfixed in 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 later · before 10.2.18-h6affectedfixed in 10.2.18-h6, 10.2.16-h7, 10.2.13-h21, 10.2.10-h36, 10.2.7-h34

  • Palo Alto Networks Prisma Access

    • Allnot affected

Same product

paloaltonetworks: all records

Other highest-scoring records for the same primary product.

  • CVE-2024-3400PAN-OS: Arbitrary File Creation Leads to OS Command Injection Vulnerability in GlobalProtectKEV
    100Now
  • CVE-2017-15944Palo Alto Networks PAN-OS before 6.1.19, 7.0.x before 7.0.19, 7.1.x before 7.1.14, and 8.0.x before 8.0.6 allows remote attackers to executeKEV
    99Now
  • CVE-2024-0012PAN-OS: Authentication Bypass in the Management Web Interface (PAN-SA-2024-0015)KEV
    97Now

Published before and after this one in the same product

  • ← EarlierCVE-2025-4615Oct 9, 2025 · PAN-OS: Improper Neutralization of Input in the Management Web Interface
    22Monitor
  • ← EarlierCVE-2026-0227Jan 15, 2026 · PAN-OS: Firewall Denial of Service (DoS) in GlobalProtect Gateway and Portal
    26Monitor
  • Later →CVE-2026-0263May 13, 2026 · PAN-OS: Remote Code Execution (RCE) in IKEv2 Processing
    28Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Palo Alto Networks PAN-OS10.2.10-h36Vendor (CNA)
Palo Alto Networks PAN-OS10.2.13-h21Vendor (CNA)
Palo Alto Networks PAN-OS10.2.16-h7Vendor (CNA)
Palo Alto Networks PAN-OS10.2.18-h6Vendor (CNA)
Palo Alto Networks PAN-OS10.2.7-h34Vendor (CNA)
Palo Alto Networks PAN-OS11.1.10-h25Vendor (CNA)
Palo Alto Networks PAN-OS11.1.13-h5Vendor (CNA)
Palo Alto Networks PAN-OS11.1.15Vendor (CNA)
Palo Alto Networks PAN-OS11.1.4-h33Vendor (CNA)
Palo Alto Networks PAN-OS11.1.6-h32Vendor (CNA)
Palo Alto Networks PAN-OS11.1.7-h6Vendor (CNA)
Palo Alto Networks PAN-OS11.2.10-h6Vendor (CNA)
Palo Alto Networks PAN-OS11.2.12Vendor (CNA)
Palo Alto Networks PAN-OS11.2.4-h17Vendor (CNA)
Palo Alto Networks PAN-OS11.2.7-h13Vendor (CNA)
Palo Alto Networks PAN-OS12.1.4-h5Vendor (CNA)
Palo Alto Networks PAN-OS12.1.7Vendor (CNA)

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

  • Proof-of-concept repository on GitHub ×10

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:32026-05-06
Proof-of-concept repository on GitHubstars:12026-05-06
Proof-of-concept repository on GitHubstars:12026-05-06
Proof-of-concept repository on GitHubstars:02026-05-06
Proof-of-concept repository on GitHubstars:42026-05-06
Proof-of-concept repository on GitHubstars:12026-05-06
Proof-of-concept repository on GitHubstars:222026-05-06
Proof-of-concept repository on GitHubstars:02026-05-21
Proof-of-concept repository on GitHubstars:22026-05-22
Proof-of-concept repository on GitHubstars:02026-08-06

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. First PoC-1 d
  2. CISA KEV-1 d
  3. Published
  4. TodayNov 3, 2026+181 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-02637 days apartPAN-OS: Remote Code Execution (RCE) in IKEv2 Processing
    28Monitor
  • CVE-2026-028863 days apartPAN-OS: Buffer Overflow Vulnerabilities in User-ID Terminal Server Agent
    28Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

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

Weakness class (CWE)

CWE-787 · Out-of-bounds Write

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:N/E:A/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:U/V:C/RE:M/U:Red

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records