Answer in brief
CVE-2025-39819 records a Medium severity (CVSS 5.5) vulnerability in fs/smb: Fix inconsistent refcnt update. 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). 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). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.17:rc3:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=a7d5c294628088781da9e91cbb034d61c3a71f71 <3fc11ff13fbc2749871d6ac2141685cf54699997 || >=a7d5c294628088781da9e91cbb034d61c3a71f71 <4191ea1f0bb3e27d65c5dcde7bd00e709ec67141 || >=a7d5c294628088781da9e91cbb034d61c3a71f71 <4735f5991f51468b85affb8366b7067248457a71 || >=a7d5c294628088781da9e91cbb034d61c3a71f71 <cc82c6dff548f0066a51a6e577c7454e7d26a968 || >=a7d5c294628088781da9e91cbb034d61c3a71f71 <ab529e6ca1f67bcf31f3ea80c72bffde2e9e053e | 3fc11ff13fbc2749871d6ac2141685cf54699997, 4191ea1f0bb3e27d65c5dcde7bd00e709ec67141, 4735f5991f51468b85affb8366b7067248457a71, cc82c6dff548f0066a51a6e577c7454e7d26a968, ab529e6ca1f67bcf31f3ea80c72bffde2e9e053e |
| Linux/Linuxgeneric | 5.8 | Not reported |
| Siemens/SIMATIC CN 4100generic | >=0 <V5.0 | V5.0 |
Published upstream
Sep 16, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 28, 2026
In the Linux kernel, the following vulnerability has been resolved: fs/smb: Fix inconsistent refcnt update A possible inconsistent update of refcount was identified in `smb2_compound_op`. Such inconsistent update could lead to possible resource leaks. Why it is a possible bug: 1. In the comment section of the function, it clearly states that the reference to `cfile` should be dropped after calling this function. 2. Every control flow path would check and drop the reference to `cfile`, except the patched one. 3. Existing callers would not handle refcount update of `cfile` if -ENOMEM is returned. To fix the bug, an extra goto label "out" is added, to make sure that the cleanup logic would always be respected. As the problem is caused by the allocation failure of `vars`, the cleanup logic between label "finished" and "out" can be safely ignored. According to the definition of function `is_replayable_error`, the error code of "-ENOMEM" is not recoverable. Therefore, the replay logic also gets ignored.
Quoted source text, attributed separately from HOL analysis.