VulnerabilityPublished 16 Jan 2026

CVE-2025-29943: AMD EPYC™ 9004 Series Processors · Write-what-where Condition

Affects AMD EPYC™ 9004 Series ProcessorsSource CVE Database V5

Not known to be exploited · CVSS 4.6 Medium.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 4.0 base score

4.6Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 13% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N

Attack Vector: Local
Attack Complexity: Low
Attack Requirements: None
Privileges Required: High
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: None
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: Low
Subsequent system availability: None

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

Attack Vector: Local: The vulnerable system is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or through terminal emulation (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., using social engineering techniques to trick a legitimate user into opening a malicious document).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
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: High: The attacker requires privileges that provide significant (e.g., administrative) control over the vulnerable system allowing full access to the vulnerable system’s settings and files.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within 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: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable 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.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 16 Jan 2026
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 26 Oct 2026.

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 or the CVSS exploit maturity 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

Affected software

Product	Affected	Fixed in
AMDAMD EPYC™ 9004 Series Processors	Affected–	Fixed in–
AMDAMD EPYC™ 9005 Series Processors	Affected–	Fixed in–
AMDAMD EPYC™ 8004 Series Processors	Affected–	Fixed in–
AMDAMD EPYC™ Embedded 7003 Series Processors	Affected–	Fixed in–
AMDAMD EPYC™ Embedded 9005 Series Processors	Affected–	Fixed in–

AI-suggested

Enforce strict administrative access controls and limit the number of users with high privileges on hosts running AMD EPYC 9004 processors.
Implement robust monitoring and auditing of administrative actions to detect suspicious behavior indicative of exploitation attempts.
Use hardware and software-based security solutions to detect anomalies in CPU pipeline behavior or virtualization integrity.
Isolate critical workloads and sensitive SEV-SNP guests on separate hosts with minimal administrative exposure.
Prepare for timely deployment of AMD patches or microcode updates once released, including testing in controlled environments.
Employ multi-factor authentication and privileged access management to reduce risk of credential compromise.
Regularly review and update virtualization and host security configurations to minimize attack surface.
Engage with AMD and security communities to stay informed on developments and recommended mitigations.

Description

Write what were condition within AMD CPUs may allow an admin-privileged attacker to modify the configuration of the CPU pipeline potentially resulting in the corruption of the stack pointer inside an SEV-SNP guest.

Impact

For European organizations, especially those operating cloud infrastructure, data centers, or virtualized environments using AMD EPYC 9004 Series processors, this vulnerability poses a risk to the confidentiality and integrity of virtual machines protected by SEV-SNP. Successful exploitation could allow an attacker with administrative privileges to corrupt critical CPU state, potentially leading to guest VM compromise or data leakage. This undermines trust in hardware-based security features and could impact sectors relying on secure virtualization, such as finance, healthcare, and government. Although the vulnerability requires high privileges and local access, insider threats or compromised administrators could exploit it. The lack of patches increases exposure time, and organizations may face compliance and reputational risks if sensitive data is compromised. The vulnerability does not directly affect availability but could lead to system instability or crashes if exploited.

Summary

CVE-2025-29943 is a write-what-where vulnerability classified under CWE-123 that affects AMD EPYC™ 9004 Series processors. This flaw allows an attacker with administrative privileges on the host system to manipulate the CPU pipeline configuration. Specifically, the vulnerability can lead to corruption of the stack pointer within an SEV-SNP (Secure Encrypted Virtualization - Secure Nested Paging) guest environment. SEV-SNP is a security feature designed to protect virtual machines by encrypting their memory and ensuring integrity. By exploiting this vulnerability, an attacker could potentially undermine the isolation guarantees provided by SEV-SNP, leading to possible compromise of guest virtual machines. The attack requires local privileged access (administrator level) and does not require user interaction, limiting the attack surface to insiders or compromised administrators. The CVSS v4.0 base score of 4.6 reflects the limited attack vector (local), low complexity, and the requirement for high privileges but no user interaction or network access. No patches or mitigations have been published by AMD at the time of disclosure, and no known exploits are reported in the wild. This vulnerability highlights risks in hardware-level security features and the importance of securing administrative access in virtualized environments.

CWE-123Write-what-where Condition (opens in a new tab)
Base weaknessLikelihood of exploit: High
Any condition where the attacker has the ability to write an arbitrary value to an arbitrary location, often as the result of a buffer overflow.
Architecture and Design · Language Selection
Use a language that provides appropriate memory abstractions.
Operation
Use OS-level preventative functionality integrated after the fact. Not a complete solution.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

amd.com/en/resources/product-security/bulletin/AMD-SB-3027.html (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 16 Jan 2026, 16:06 UTC

WeaknessesCWE-123

Technical details

References

Community reviews

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