CVE-2025-39964
In the Linux kernel, the following vulnerability has been resolved: crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg Issuing two writes to the same af_alg socket is bogus as the data will be interleaved in an unpredictable fashion. Furthermore, concurrent writes may create inconsistencies in the internal socket state. Disallow this by adding a new ctx->write field that indiciates exclusive ownership for writing.
Actively exploited
- In the CISA exploited-vulnerabilities catalogue since Sep 18, 2026
- US federal agencies must remediate it by Sep 21, 2026 (BOD 22-01)
- First attack observed 339 days after disclosure
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Source: CISA KEV · Sep 18, 2026
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HAffected products
| Vendors | Product | Versions |
|---|---|---|
| linux | linux kernel | < 5.10.245 |
| siemens | simatic s7-1500 cpu 1518-4 pn\/dp mfp firmware | — |
| siemens | simatic s7-1500 cpu 1518-4 pn\/dp mfp | — |
| siemens | simatic s7-1500 cpu 1518f-4 pn\/dp mfp firmware | — |
| siemens | simatic s7-1500 cpu 1518f-4 pn\/dp mfp | — |
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