CVE-2021-26356
HIGHCVSS 7.4/10EPSS 0.40%
Last modified
CVE-2021-26356 is a high-severity vulnerability rated 7.4/10 on the CVSS scale. A TOCTOU in ASP bootloader may allow an attacker to tamper with the SPI ROM following data read to memory potentially resulting in S3 data corruption and information disclosure. . EPSS estimates a 0.40% chance of exploitation in the next 30 days.
Description
A TOCTOU in ASP bootloader may allow an attacker to tamper with the SPI ROM following data read to memory potentially resulting in S3 data corruption and information disclosure.
Metrics
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Amd | Epyc 7001 Firmware | < naplespi_1.0.0.h |
| Amd | Epyc 7251 Firmware | < naplespi_1.0.0.h |
| Amd | Epyc 7261 Firmware | < naplespi_1.0.0.h |
| Amd | Epyc 7281 Firmware | < naplespi_1.0.0.h |
| Amd | Epyc 7301 Firmware | < naplespi_1.0.0.h |
| Amd | Epyc 7351 Firmware | < naplespi_1.0.0.h |
| Amd | Epyc 7351p Firmware | < naplespi_1.0.0.h |
| Amd | Epyc 7371 Firmware | < naplespi_1.0.0.h |
| Amd | Epyc 7401 Firmware | < naplespi_1.0.0.h |
| Amd | Epyc 7401p Firmware | < naplespi_1.0.0.h |
| Amd | Epyc 7451 Firmware | < naplespi_1.0.0.h |
| Amd | Epyc 7501 Firmware | < naplespi_1.0.0.h |
| Amd | Epyc 7551 Firmware | < naplespi_1.0.0.h |
| Amd | Epyc 7551p Firmware | < naplespi_1.0.0.h |
| Amd | Epyc 7601 Firmware | < naplespi_1.0.0.h |
| Amd | Epyc 7002 Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7232p Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7252 Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7262 Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7272 Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7282 Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7302 Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7302p Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7352 Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7402 Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7402p Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7452 Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7502 Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7532 Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7542 Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7552 Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7642 Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7662 Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7702 Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7702p Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7f32 Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7f52 Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7f72 Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7h12 Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7742 Firmware | < romepi_1.0.0.d |
| Amd | Epyc 7773x Firmware | < milanpi_1.0.0.6 |
| Amd | Epyc 7763 Firmware | < milanpi_1.0.0.6 |
| Amd | Epyc 7713p Firmware | < milanpi_1.0.0.6 |
| Amd | Epyc 7713 Firmware | < milanpi_1.0.0.6 |
| Amd | Epyc 7663 Firmware | < milanpi_1.0.0.6 |
| Amd | Epyc 7643 Firmware | < milanpi_1.0.0.6 |
| Amd | Epyc 75f3 Firmware | < milanpi_1.0.0.6 |
| Amd | Epyc 7573x Firmware | < milanpi_1.0.0.6 |
| Amd | Epyc 7543p Firmware | < milanpi_1.0.0.6 |
| Amd | Epyc 7543 Firmware | < milanpi_1.0.0.6 |
Showing 50 of 98 affected configurations. See NVD for the full list.
References
Timeline
- Published
- Last Modified
- Status
- Modified
Frequently Asked Questions
What is CVE-2021-26356?
A TOCTOU in ASP bootloader may allow an attacker
to tamper with the SPI ROM following data read to memory potentially resulting
in S3 data corruption and information disclosure.
How severe is CVE-2021-26356?
CVE-2021-26356 has a CVSS score of 7.4/10 (HIGH severity). The EPSS model estimates a 0.40% probability of exploitation in the next 30 days.
How do I fix CVE-2021-26356?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
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Are you affected by CVE-2021-26356?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST