Answer in brief
CVE-2025-21640 records a High severity (CVSS 7.1) 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.
CVSS is 7.1. 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.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.13:rc1:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.13:rc2:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.13:rc3:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.13:rc4:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.13:rc5:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.13:rc6:*:*:*:*:*:* | Not reported | Not reported |
| 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
Oct 15, 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.