CVE-2026-0263: Palo Alto Networks Cloud NGFW · Out-of-bounds Write

Attack Vector: Network

The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).

Attack Complexity: High

The successful attack depends on the evasion or circumvention of security-enhancing techniques in place that would otherwise hinder the attack. These include: Evasion of exploit mitigation techniques, for example, circumvention of address space randomization (ASLR) or data execution prevention (DEP) must be performed for the attack to be successful; Obtaining target-specific secrets. The attacker must gather some target-specific secret before the attack can be successful. A secret is any piece of information that cannot be obtained through any amount of reconnaissance. To obtain the secret the attacker must perform additional attacks or break otherwise secure measures (e.g. knowledge of a secret key may be needed to break a crypto channel). This operation must be performed for each attacked target.

Attack Requirements: None

The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.

Privileges Required: None

The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.

User Interaction: None

The vulnerable system can be exploited without interaction from any human user, other than the attacker.

Vulnerable system confidentiality: High

There is a total loss of confidentiality, resulting in all information within the Vulnerable System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.

Vulnerable system integrity: High

There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the vulnerable system. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the vulnerable system.

Vulnerable system availability: High

There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the Vulnerable System; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the Vulnerable System (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Subsequent system confidentiality: Low

There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Subsequent System.

Subsequent system integrity: Low

Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Subsequent System.

Subsequent system availability: None

There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Exploit Maturity: Unreported

Based on threat intelligence sources each of the following must apply: · No knowledge of publicly available proof-of-concept · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Automatable: Yes

Attackers can reliably automate all 4 steps of the kill chain. These steps are reconnaissance, weaponization, delivery, and exploitation (e.g., the vulnerability is “wormable”).

Recovery: User

The system requires manual intervention by the user to recover services, after an attack has been performed.

Value Density: Concentrated

The vulnerable system is rich in resources. Heuristically, such systems are often the direct responsibility of “system operators” rather than users. An example of Concentrated (think: broad) Value Density would be an attack on a central email server.

Vulnerability Response Effort: High

The actions required to respond to a vulnerability are significant and/or difficult, and may possibly lead to an extended, scheduled service impact. This would need to be considered for scheduling purposes including honoring any embargo on deployment of the selected response. Alternatively, response to the vulnerability in the field is not possible remotely. The only resolution to the vulnerability involves physical replacement (e.g. units deployed would have to be recalled for a depot level repair or replacement). Examples include: a highly privileged driver update, microcode or UEFI BIOS updates, or software upgrades requiring careful analysis and understanding of any potential infrastructure impact before implementation. A UEFI BIOS update that impacts Trusted Platform Module (TPM) attestation without impacting disk encryption software such as Bit locker is a good recent example. Irreparable failures such as non-bootable flash subsystems, failed disks or solid-state drives (SSD), bad memory modules, network devices, or other non-recoverable under warranty hardware, should also be scored as having a High effort.

Provider Urgency: Red

Provider has assessed the impact of this vulnerability as having the highest urgency.

Definitions: FIRST CVSS v4.0 specification.