LiveActive security incident?Get immediate response
CVE Record

CVE-2025-71203: riscv: Sanitize syscall table indexing under speculation

In the Linux kernel, the following vulnerability has been resolved: riscv: Sanitize syscall table indexing under speculation The syscall number is a user-controlled value used to index into the syscall table. Use array_index_nospec() to clamp this value after the bounds check to prevent speculative out-of-bounds access and subsequent data leakage via cache side channels.

UnknownCVSS not scoredNot KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2025-71203 is a Linux kernel issue on RISC-V systems. A user-controlled syscall number could be used speculatively to access outside the syscall table, creating a possible cache side-channel data leak. The sources do not provide CVSS, confirmed exploitation, or detailed impact scope.

Executive priority

Treat as a monitoring and patch-planning item unless RISC-V systems host sensitive or multi-tenant workloads. Business urgency is uncertain because no CVSS score, confirmed exploitation, or complete vendor remediation matrix is provided.

Technical view

The RISC-V syscall path used a user-controlled syscall number for syscall-table indexing. The fix applies array_index_nospec() after bounds checking, clamping speculative execution and reducing risk of out-of-bounds speculative access and cache side-channel leakage.

Likely exposure

Exposure appears limited to Linux deployments running affected RISC-V kernel versions or downstream builds containing the vulnerable syscall-table indexing behavior. Non-RISC-V systems are not indicated as affected by the provided sources.

Exploitation context

The CVE record does not indicate active exploitation, and KEV status is false. The described risk is speculative out-of-bounds access followed by possible data leakage via cache side channels. No exploit maturity or attack prerequisites are provided.

Researcher notes

The core issue is speculative execution bypassing a bounds-checked syscall-table index. The source confirms array_index_nospec() as the remediation pattern. Researchers should avoid assuming exploitability beyond the stated cache side-channel leakage risk without architecture and kernel-build validation.

Mitigation direction

  • Identify RISC-V Linux systems and their exact kernel build versions.
  • Check vendor or distribution advisories for fixed kernels containing the referenced stable commits.
  • Prioritize kernel updates where RISC-V systems process sensitive workloads.
  • Apply defense-in-depth controls for shared, multi-tenant RISC-V environments.
  • Track CVE updates because severity and CVSS are currently absent.

Validation and detection

  • Inventory RISC-V Linux hosts, appliances, and embedded images.
  • Compare running kernel versions against vendor fixed-release guidance.
  • Confirm whether downstream kernels include the referenced stable fixes.
  • Review vulnerability scanner findings for CVE-2025-71203 once signatures are available.
  • Document systems deferred from patching and compensating controls.
Prepared
Confidence
medium
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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.

cve · low confidence lookup

CVE-2025-71203 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

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.

0CVSS vectors
3Timeline events
0ADP providers
5Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxf0bddf50586da81360627a772be0e355b62f071e, f0bddf50586da81360627a772be0e355b62f071e, f0bddf50586da81360627a772be0e355b62f071e, f0bddf50586da81360627a772be0e355b62f071eunaffected
LinuxLinux6.4, 0, 6.6.130, 6.12.70, 6.18.10, 6.19affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.