Answer in brief
CVE-2025-21640 records a Unknown severity vulnerability in sctp: sysctl: cookie_hmac_alg: avoid using current->nsproxy. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystem (generic). 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-2025-21640 records a Unknown severity vulnerability in sctp: sysctl: cookie_hmac_alg: avoid using current->nsproxy. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystem (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), Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystem (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=3c68198e75111a905ac2412be12bf7b29099729b <5599b212d2f4466e1832a94e9932684aaa364587 || >=3c68198e75111a905ac2412be12bf7b29099729b <03ca51faba2b017bf6c90e139434c4117d0afcdc || >=3c68198e75111a905ac2412be12bf7b29099729b <86ddf8118123cb58a0fb8724cad6979c4069065b || >=3c68198e75111a905ac2412be12bf7b29099729b <3cd0659deb9c03535fd61839e91d4d4d3e51ac71 || >=3c68198e75111a905ac2412be12bf7b29099729b <ad673e514b2793b8d5902f6ba6ab7e890dea23d5 || >=3c68198e75111a905ac2412be12bf7b29099729b <f0bb3935470684306e4e04793a20ac4c4b08de0b || >=3c68198e75111a905ac2412be12bf7b29099729b <ea62dd1383913b5999f3d16ae99d411f41b528d4 | 5599b212d2f4466e1832a94e9932684aaa364587, 03ca51faba2b017bf6c90e139434c4117d0afcdc, 86ddf8118123cb58a0fb8724cad6979c4069065b, 3cd0659deb9c03535fd61839e91d4d4d3e51ac71, ad673e514b2793b8d5902f6ba6ab7e890dea23d5, f0bb3935470684306e4e04793a20ac4c4b08de0b, ea62dd1383913b5999f3d16ae99d411f41b528d4 |
| Linux/Linuxgeneric | 3.8 | Not reported |
| Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystemgeneric | >=0 <* | * |
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: cookie_hmac_alg: 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, as this is the only member needed from the 'net' structure, but that would increase the size of this fix, to use '*data' everywhere 'net->sctp.sctp_hmac_alg' is used.
Quoted source text, attributed separately from HOL analysis.
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), Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystem (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=3c68198e75111a905ac2412be12bf7b29099729b <5599b212d2f4466e1832a94e9932684aaa364587 || >=3c68198e75111a905ac2412be12bf7b29099729b <03ca51faba2b017bf6c90e139434c4117d0afcdc || >=3c68198e75111a905ac2412be12bf7b29099729b <86ddf8118123cb58a0fb8724cad6979c4069065b || >=3c68198e75111a905ac2412be12bf7b29099729b <3cd0659deb9c03535fd61839e91d4d4d3e51ac71 || >=3c68198e75111a905ac2412be12bf7b29099729b <ad673e514b2793b8d5902f6ba6ab7e890dea23d5 || >=3c68198e75111a905ac2412be12bf7b29099729b <f0bb3935470684306e4e04793a20ac4c4b08de0b || >=3c68198e75111a905ac2412be12bf7b29099729b <ea62dd1383913b5999f3d16ae99d411f41b528d4 | 5599b212d2f4466e1832a94e9932684aaa364587, 03ca51faba2b017bf6c90e139434c4117d0afcdc, 86ddf8118123cb58a0fb8724cad6979c4069065b, 3cd0659deb9c03535fd61839e91d4d4d3e51ac71, ad673e514b2793b8d5902f6ba6ab7e890dea23d5, f0bb3935470684306e4e04793a20ac4c4b08de0b, ea62dd1383913b5999f3d16ae99d411f41b528d4 |
| Linux/Linuxgeneric | 3.8 | Not reported |
| Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystemgeneric | >=0 <* | * |
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: cookie_hmac_alg: 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, as this is the only member needed from the 'net' structure, but that would increase the size of this fix, to use '*data' everywhere 'net->sctp.sctp_hmac_alg' is used.
Quoted source text, attributed separately from HOL analysis.