CVE-2026-56130: Apache Shiro · Authentication Bypass by Capture-replay

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: Low

The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.

User Interaction: Active

Successful exploitation of this vulnerability requires a targeted user to perform specific, conscious interactions with the vulnerable system and the attacker’s payload, or the user’s interactions would actively subvert protection mechanisms which would lead to exploitation of the vulnerability.

Vulnerable 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 Vulnerable System.

Vulnerable system integrity: None

There is no loss of integrity within the Vulnerable System.

Vulnerable system availability: None

There is no impact to availability within the Vulnerable System.

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: None

There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable 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.

Safety: Negligible

Consequences of the vulnerability meet definition of IEC 61508 consequence category "negligible."

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”).

Value Density: Diffuse

The vulnerable system has limited resources. That is, the resources that the attacker will gain control over with a single exploitation event are relatively small. An example of Diffuse (think: limited) Value Density would be an attack on a single email client vulnerability.

Vulnerability Response Effort: Low

The effort required to respond to a vulnerability is low/trivial. Examples include: communication on better documentation, configuration workarounds, or guidance from the vendor that does not require an immediate update, upgrade, or replacement by the consuming entity, such as firewall filter configuration.

Provider Urgency: Green

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

Definitions: FIRST CVSS v4.0 specification.