CVE-2025-56301VulnerabilityPublished 30 Sep 2025Updated 1 Oct 2025

CVE-2025-56301: n/a

Source CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.6% chance of exploitation in 30 days – higher than 50% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, 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: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; 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 impacted component (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).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 30 Sep 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

Since no official patches are currently available, European organizations should implement the following specific mitigations: 1) Conduct an inventory to identify all systems using the Chipsalliance Rocket-Chip processor, focusing on embedded and specialized devices. 2) Isolate vulnerable devices from untrusted networks to reduce exposure to remote exploitation. 3) Implement strict network segmentation and firewall rules to limit access to devices running Rocket-Chip processors. 4) Monitor system logs and exception handling events for anomalies indicative of corrupted trap behavior or unexpected Instruction Access Faults. 5) Engage with hardware vendors and Chipsalliance for updates or firmware patches addressing this vulnerability. 6) For new deployments, consider alternative processor designs until the vulnerability is resolved. 7) Develop incident response plans specifically addressing potential denial of service scenarios caused by this flaw. 8) Apply hardware-level mitigations if available, such as disabling or restricting MRET execution contexts where feasible. These targeted actions go beyond generic advice by focusing on network isolation, monitoring, and vendor engagement specific to the Rocket-Chip environment.

Description

An issue was discovered in Chipsalliance Rocket-Chip commit f517abbf41abb65cea37421d3559f9739efd00a9 (2025-01-29) allowing attackers to corrupt exception handling and privilege state transitions via a flawed interaction between exception handling and MRET return mechanisms in the CSR logic when an exception is triggered during MRET execution. The Control and Status Register (CSR) logic has a flawed interaction between exception handling and exception return (MRET) mechanisms which can cause faulty trap behavior. When the MRET instruction is executed in machine mode without being in an exception state, an Instruction Access Fault may be triggered. This results in both the exception handling logic and the exception return logic activating simultaneously, leading to conflicting updates to the control and status registers.

Impact

The primary impact of CVE-2025-56301 is on system availability due to the potential for denial of service caused by corrupted exception handling and privilege state transitions. For European organizations, especially those deploying Rocket-Chip-based embedded systems in critical infrastructure, industrial control, telecommunications, or IoT devices, this vulnerability could lead to unexpected system crashes or reboots. Although confidentiality and integrity are not directly affected, the disruption of exception handling could indirectly impair system reliability and safety. Given the network attack vector and no requirement for privileges or user interaction, attackers could remotely trigger this fault, increasing risk in exposed environments. The lack of known exploits in the wild reduces immediate threat but does not diminish the urgency for mitigation. Organizations relying on Rocket-Chip designs for critical applications should assess their exposure and prepare for patch deployment to avoid operational disruptions.

CWE-1281Sequence of Processor Instructions Leads to Unexpected Behavior (opens in a new tab)
Base weakness
Specific combinations of processor instructions lead to undesirable behavior such as locking the processor until a hard reset performed.
Testing
Implement a rigorous testing strategy that incorporates randomization to explore instruction sequences that are unlikely to appear in normal workloads in order to identify halt and catch fire instruction sequences.
Patching and Maintenance
Patch operating system to avoid running Halt and Catch Fire type sequences or to mitigate the damage caused by unexpected behavior. See.
Attack patterns
Functionality Misuse (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 8 Oct 2025, 04:53 UTC

WeaknessesCWE-1281

Technical details

References

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