Answer in brief
CVE-2025-39681 records a Medium severity (CVSS 5.5) vulnerability in x86/cpu/hygon: Add missing resctrl_cpu_detect() in bsp_init helper. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC CN 4100 (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2025-39681 records a Medium severity (CVSS 5.5) vulnerability in x86/cpu/hygon: Add missing resctrl_cpu_detect() in bsp_init helper. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC CN 4100 (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC CN 4100 (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 <62f12cde10118253348a7540e85606869bd69432 || >=923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 <873f32201df8876bdb2563e3187e79149427cab4 || >=923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 <fb81222c1559f89bfe3aa1010f6d112531d55353 || >=923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 <7207923d8453ebfb35667c1736169f2dd796772e || >=923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 <a9e5924daa954c9f585c1ca00358afe71d6781c4 || >=923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 <d23264c257a70dbe021b43b3bc2ee16134cd2c69 || >=923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 <d8df126349dad855cdfedd6bbf315bad2e901c2f | 62f12cde10118253348a7540e85606869bd69432, 873f32201df8876bdb2563e3187e79149427cab4, fb81222c1559f89bfe3aa1010f6d112531d55353, 7207923d8453ebfb35667c1736169f2dd796772e, a9e5924daa954c9f585c1ca00358afe71d6781c4, d23264c257a70dbe021b43b3bc2ee16134cd2c69, d8df126349dad855cdfedd6bbf315bad2e901c2f |
| Linux/Linuxgeneric | 5.8 | Not reported |
| Siemens/SIMATIC CN 4100generic | >=0 <V5.0 | V5.0 |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
Published upstream
Sep 5, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 14, 2026
In the Linux kernel, the following vulnerability has been resolved: x86/cpu/hygon: Add missing resctrl_cpu_detect() in bsp_init helper Since 923f3a2b48bd ("x86/resctrl: Query LLC monitoring properties once during boot") resctrl_cpu_detect() has been moved from common CPU initialization code to the vendor-specific BSP init helper, while Hygon didn't put that call in their code. This triggers a division by zero fault during early booting stage on our machines with X86_FEATURE_CQM* supported, where get_rdt_mon_resources() tries to calculate mon_l3_config with uninitialized boot_cpu_data.x86_cache_occ_scale. Add the missing resctrl_cpu_detect() in the Hygon BSP init helper. [ bp: Massage commit message. ]
Quoted source text, attributed separately from HOL analysis.
CVSS is 5.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC CN 4100 (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 <62f12cde10118253348a7540e85606869bd69432 || >=923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 <873f32201df8876bdb2563e3187e79149427cab4 || >=923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 <fb81222c1559f89bfe3aa1010f6d112531d55353 || >=923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 <7207923d8453ebfb35667c1736169f2dd796772e || >=923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 <a9e5924daa954c9f585c1ca00358afe71d6781c4 || >=923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 <d23264c257a70dbe021b43b3bc2ee16134cd2c69 || >=923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 <d8df126349dad855cdfedd6bbf315bad2e901c2f | 62f12cde10118253348a7540e85606869bd69432, 873f32201df8876bdb2563e3187e79149427cab4, fb81222c1559f89bfe3aa1010f6d112531d55353, 7207923d8453ebfb35667c1736169f2dd796772e, a9e5924daa954c9f585c1ca00358afe71d6781c4, d23264c257a70dbe021b43b3bc2ee16134cd2c69, d8df126349dad855cdfedd6bbf315bad2e901c2f |
| Linux/Linuxgeneric | 5.8 | Not reported |
| Siemens/SIMATIC CN 4100generic | >=0 <V5.0 | V5.0 |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
Published upstream
Sep 5, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 14, 2026
In the Linux kernel, the following vulnerability has been resolved: x86/cpu/hygon: Add missing resctrl_cpu_detect() in bsp_init helper Since 923f3a2b48bd ("x86/resctrl: Query LLC monitoring properties once during boot") resctrl_cpu_detect() has been moved from common CPU initialization code to the vendor-specific BSP init helper, while Hygon didn't put that call in their code. This triggers a division by zero fault during early booting stage on our machines with X86_FEATURE_CQM* supported, where get_rdt_mon_resources() tries to calculate mon_l3_config with uninitialized boot_cpu_data.x86_cache_occ_scale. Add the missing resctrl_cpu_detect() in the Hygon BSP init helper. [ bp: Massage commit message. ]
Quoted source text, attributed separately from HOL analysis.