Answer in brief
CVE-2025-21836 records a Unknown severity vulnerability in io_uring/kbuf: reallocate buf lists on upgrade. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. 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). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=2fcabce2d7d34f69a888146dab15b36a917f09d4 <146a185f6c05ee263db715f860620606303c4633 || >=2fcabce2d7d34f69a888146dab15b36a917f09d4 <7d0dc28dae836caf7645fef62a10befc624dd17b || >=2fcabce2d7d34f69a888146dab15b36a917f09d4 <2a5febbef40ce968e295a7aeaa5d5cbd9e3e5ad4 || >=2fcabce2d7d34f69a888146dab15b36a917f09d4 <8802766324e1f5d414a81ac43365c20142e85603 | 146a185f6c05ee263db715f860620606303c4633, 7d0dc28dae836caf7645fef62a10befc624dd17b, 2a5febbef40ce968e295a7aeaa5d5cbd9e3e5ad4, 8802766324e1f5d414a81ac43365c20142e85603 |
| Linux/Linuxgeneric | 5.19 | Not reported |
Published upstream
Mar 7, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: io_uring/kbuf: reallocate buf lists on upgrade IORING_REGISTER_PBUF_RING can reuse an old struct io_buffer_list if it was created for legacy selected buffer and has been emptied. It violates the requirement that most of the field should stay stable after publish. Always reallocate it instead.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2025-21836 records a Unknown severity vulnerability in io_uring/kbuf: reallocate buf lists on upgrade. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. 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). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=2fcabce2d7d34f69a888146dab15b36a917f09d4 <146a185f6c05ee263db715f860620606303c4633 || >=2fcabce2d7d34f69a888146dab15b36a917f09d4 <7d0dc28dae836caf7645fef62a10befc624dd17b || >=2fcabce2d7d34f69a888146dab15b36a917f09d4 <2a5febbef40ce968e295a7aeaa5d5cbd9e3e5ad4 || >=2fcabce2d7d34f69a888146dab15b36a917f09d4 <8802766324e1f5d414a81ac43365c20142e85603 | 146a185f6c05ee263db715f860620606303c4633, 7d0dc28dae836caf7645fef62a10befc624dd17b, 2a5febbef40ce968e295a7aeaa5d5cbd9e3e5ad4, 8802766324e1f5d414a81ac43365c20142e85603 |
| Linux/Linuxgeneric | 5.19 | Not reported |
Published upstream
Mar 7, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: io_uring/kbuf: reallocate buf lists on upgrade IORING_REGISTER_PBUF_RING can reuse an old struct io_buffer_list if it was created for legacy selected buffer and has been emptied. It violates the requirement that most of the field should stay stable after publish. Always reallocate it instead.
Quoted source text, attributed separately from HOL analysis.