CVE-2025-39964
crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg
Reported by linux · Published October 13, 2025
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.
Fixed versions
Upgrade to a fixed version or later. Language registries are listed first, then Linux distributions, then vendor products.
| Package | Ecosystem | Fixed in |
|---|---|---|
| kernel-rt-devel | errata.rockylinux.org | 6.12.0-211.58.1.el10, 5.14.0-687.50.1.el9, 4.18.0-553.166.1.rt7.507.el8 |
| kernel-modules-extra | errata.rockylinux.org | 5.14.0-687.50.1.el9, 4.18.0-553.166.1.el8 |
| kernel-64k-modules-extra | errata.rockylinux.org | 6.12.0-211.58.1.el10 |
| kernel-debuginfo | errata.rockylinux.org | 6.12.0-211.58.1.el10, 4.18.0-553.166.1.el8 |
| kernel-tools | errata.rockylinux.org | 5.14.0-687.50.1.el9 |
| python3-perf | errata.rockylinux.org | 6.12.0-211.58.1.el10, 5.14.0-687.50.1.el9, 4.18.0-553.166.1.el8 |
| libperf-debuginfo | errata.rockylinux.org | 6.12.0-211.58.1.el10, 5.14.0-687.50.1.el9 |
| kernel-debug-modules-extra | errata.rockylinux.org | 4.18.0-553.166.1.el8 |
| kernel-64k-debug-modules-extra | errata.rockylinux.org | 5.14.0-687.50.1.el9 |
| libperf | errata.rockylinux.org | 6.12.0-211.58.1.el10, 5.14.0-687.50.1.el9 |
| kernel-debuginfo-common-ppc64le | errata.rockylinux.org | 6.12.0-211.58.1.el10 |
| kernel-debuginfo-common-s390x | errata.rockylinux.org | 6.12.0-211.58.1.el10 |
52 more packages have a fixed version. See every fix in Lookup.
Risk scores
Affected products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | 8ff590903d5fc7f5a0a988c38267a3d08e6393a2, 8ff590903d5fc7f5a0a988c38267a3d08e6393a2, 8ff590903d5fc7f5a0a988c38267a3d08e6393a2 |
| Linux | Linux | 2.6.38, 0, 5.10.245 |
| amazon:2023 | kernel6.12-modules-extra-common | 0 |
| amazon:2023 | bpftool6.12 | 0 |
| amazon:2023 | kernel-modules-extra-common | 0 |
| amazon:2023 | perf | 0 |
| amazon:2023 | kernel6.12-modules-extra | 0 |
| chainguard | linux-desktop-7.2 | 0 |
| amazon:2023 | kernel6.12-headers | 0 |
| amazon:2023 | kernel6.12-libbpf-devel | 0 |
| amazon:2023 | kernel6.12-libbpf | 0 |
| chainguard | linux-qemu-6.12 | 0 |
| chainguard | linux-qemu-6.18 | 0 |
| chainguard | linux-vmware-6.18 | 0 |
| chainguard | linux-azure-6.12 | 0 |
| Linux | Linux | 6.17, 5.10.245, 0 |
| chainguard | linux-raspberry-pi-4 | 0 |
| chainguard | linux-qemu-melange | 0 |
| chainguard | linux-gcp-6.12 | 0 |
| amazon:2023 | kernel6.12-devel | 0 |
…and 31 more
Timeline
- May 2, 2025 VulnCheck XDB Entry (13 in total, the first dated here)
- Jul 29, 2025 VulnCheck KEV Exploitation (6 in total, the first dated here)
- Oct 13, 2025 Coalition ESS Score (14 in total, the first dated here)
- Oct 13, 2025 CVE Published
- Oct 14, 2025 EPSS Score (30 in total, the first dated here)
- Dec 15, 2025 Security Advisory (152 in total, the first dated here)
- Jan 14, 2026 PoC Published
- Apr 20, 2026 Distribution Patch (80 in total, the first dated here)
- Sep 18, 2026 CISA KEV Added
Query this with the API
The same record, from the CLI:
vulnetix vdb vuln CVE-2025-39964
vulnetix vdb fixes CVE-2025-39964Or with curl, using the org id and key from your account page:
curl -s -H "Authorization: ApiKey ${VULNETIX_ORG_ID}:${VULNETIX_API_KEY}" \
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