Security readout for executives and security teams
Plain-English summary
This flaw affects AMD Secure Processor bootloader firmware on some Ryzen 5000 Series platforms. A local attacker with low privileges could trigger a firmware-level denial of service. The reported impact is availability only, not data theft or privilege escalation.
Executive priority
Treat this as a scheduled firmware-risk remediation, not an emergency incident, unless affected systems support critical operations or shared-user environments. Prioritize inventory and vendor firmware validation first.
Technical view
CVE-2021-26346 is a CWE-190 integer overflow caused by insufficient validation of an integer operand in the ASP bootloader. AMD describes possible corruption of the L2 directory table in SPI flash, resulting in denial of service. CVSS 3.1 is 5.5: local attack, low complexity, low privileges, no user interaction, high availability impact.
Likely exposure
Exposure is likely limited to AMD Ryzen 5000 Series systems using affected AGESA firmware. The source bundle does not identify specific motherboard models, BIOS builds, or OEM firmware versions, so asset-level exposure requires vendor and OEM firmware verification.
Exploitation context
The CVE is not listed in KEV, and the provided sources do not claim active exploitation. The CVSS vector indicates local access with low privileges is required, reducing remote attack urgency but keeping availability risk relevant for shared or high-value endpoints.
Researcher notes
Evidence is limited to AMD and CVE records. The affected entry names Ryzen 5000 Series and AGESA broadly, without exact version ranges. Avoid assuming exploitability across all Ryzen 5000 systems until OEM firmware mappings are confirmed.
Mitigation direction
- Review AMD SB-1031 and OEM BIOS advisories for affected AGESA firmware.
- Apply vendor-approved BIOS or AGESA updates when available for affected Ryzen 5000 systems.
- Restrict local user access on sensitive systems until firmware exposure is confirmed.
- Use only official AMD, motherboard vendor, or OEM firmware sources.
Validation and detection
- Inventory systems running AMD Ryzen 5000 Series processors.
- Record motherboard or OEM model, BIOS version, and AGESA version where available.
- Compare firmware versions against AMD SB-1031 and relevant OEM advisories.
- After updating, confirm the BIOS or AGESA version changed successfully.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-190: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-26346 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H1.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.5MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-1031CVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Integer Overflow or Wraparound
Integer Overflow or Wraparound represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.