Answer in brief
CVE-2025-21637 records a Unknown severity vulnerability in sctp: sysctl: udp_port: avoid using current->nsproxy. 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 | >=046c052b475e7119b6a30e3483e2888fc606a2f8 <0a0966312ac3eedd7f5f2a766ed4702df39a9a65 || >=046c052b475e7119b6a30e3483e2888fc606a2f8 <e919197fb8616331f5dc81e4c3cc3d12769cb725 || >=046c052b475e7119b6a30e3483e2888fc606a2f8 <55627918febdf9d71107a1e68d1528dc591c9a15 || >=046c052b475e7119b6a30e3483e2888fc606a2f8 <5b77d73f3be5102720fb685b9e6900e3500e1096 || >=046c052b475e7119b6a30e3483e2888fc606a2f8 <c10377bbc1972d858eaf0ab366a311b39f8ef1b6 | 0a0966312ac3eedd7f5f2a766ed4702df39a9a65, e919197fb8616331f5dc81e4c3cc3d12769cb725, 55627918febdf9d71107a1e68d1528dc591c9a15, 5b77d73f3be5102720fb685b9e6900e3500e1096, c10377bbc1972d858eaf0ab366a311b39f8ef1b6 |
| Linux/Linuxgeneric | 5.11 | Not reported |
Published upstream
Jan 19, 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: sctp: sysctl: udp_port: avoid using current->nsproxy As mentioned in a previous commit of this series, using the 'net' structure via 'current' is not recommended for different reasons: - Inconsistency: getting info from the reader's/writer's netns vs only from the opener's netns. - current->nsproxy can be NULL in some cases, resulting in an 'Oops' (null-ptr-deref), e.g. when the current task is exiting, as spotted by syzbot [1] using acct(2). The 'net' structure can be obtained from the table->data using container_of(). Note that table->data could also be used directly, but that would increase the size of this fix, while 'sctp.ctl_sock' still needs to be retrieved from 'net' structure.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2025-21637 records a Unknown severity vulnerability in sctp: sysctl: udp_port: avoid using current->nsproxy. 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 | >=046c052b475e7119b6a30e3483e2888fc606a2f8 <0a0966312ac3eedd7f5f2a766ed4702df39a9a65 || >=046c052b475e7119b6a30e3483e2888fc606a2f8 <e919197fb8616331f5dc81e4c3cc3d12769cb725 || >=046c052b475e7119b6a30e3483e2888fc606a2f8 <55627918febdf9d71107a1e68d1528dc591c9a15 || >=046c052b475e7119b6a30e3483e2888fc606a2f8 <5b77d73f3be5102720fb685b9e6900e3500e1096 || >=046c052b475e7119b6a30e3483e2888fc606a2f8 <c10377bbc1972d858eaf0ab366a311b39f8ef1b6 | 0a0966312ac3eedd7f5f2a766ed4702df39a9a65, e919197fb8616331f5dc81e4c3cc3d12769cb725, 55627918febdf9d71107a1e68d1528dc591c9a15, 5b77d73f3be5102720fb685b9e6900e3500e1096, c10377bbc1972d858eaf0ab366a311b39f8ef1b6 |
| Linux/Linuxgeneric | 5.11 | Not reported |
Published upstream
Jan 19, 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: sctp: sysctl: udp_port: avoid using current->nsproxy As mentioned in a previous commit of this series, using the 'net' structure via 'current' is not recommended for different reasons: - Inconsistency: getting info from the reader's/writer's netns vs only from the opener's netns. - current->nsproxy can be NULL in some cases, resulting in an 'Oops' (null-ptr-deref), e.g. when the current task is exiting, as spotted by syzbot [1] using acct(2). The 'net' structure can be obtained from the table->data using container_of(). Note that table->data could also be used directly, but that would increase the size of this fix, while 'sctp.ctl_sock' still needs to be retrieved from 'net' structure.
Quoted source text, attributed separately from HOL analysis.