crypto: af_alg - Set merge to zero early in af_alg_sendmsg
Priority LOW 35CWE-908Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 4 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: crypto: af_alg - Set merge to zero early in af_alg_sendmsg If an error causes af_alg_sendmsg to abort, ctx->merge may contain a garbage value from the previous loop. This may then trigger a crash on the next entry into af_alg_sendmsg when it attempts to do a merge that can't be done. Fix this by setting ctx->merge to zero near the start of the loop.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00169 6th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.10.260, 5.15.211, 6.1.154 +4Red Hat: 4 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 2.6.38 and later | 5.10.260, 5.15.211, 6.1.154, 6.6.108, 6.12.49, 6.16.9, 6.17 | Patch available | CNA |
- Linux VendorLinux Affected 2.6.38 and later Fixed in 5.10.260, 5.15.211, 6.1.154, 6.6.108, 6.12.49, 6.16.9, 6.17 Patch available CNA
CPE configurations NVD · 7
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 2.6.38 to before 6.1.154; 6.2 to before 6.6.108; 6.7 to before 6.12.49; 6.13 to before 6.16.9 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:* | 6.17 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:* | 6.17 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.17:rc3:*:*:*:*:*:* | 6.17 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.17:rc4:*:*:*:*:*:* | 6.17 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.17:rc5:*:*:*:*:*:* | 6.17 rc5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.17:rc6:*:*:*:*:*:* | 6.17 rc6 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 2.6.38 to before 6.1.154; 6.2 to before 6.6.108; 6.7 to before 6.12.49; 6.13 to before 6.16.9 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:* Versions 6.17 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:* Versions 6.17 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.17:rc3:*:*:*:*:*:* Versions 6.17 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.17:rc4:*:*:*:*:*:* Versions 6.17 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.17:rc5:*:*:*:*:*:* Versions 6.17 rc5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.17:rc6:*:*:*:*:*:* Versions 6.17 rc6 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.260, 5.15.211, 6.1.154, 6.6.108, 6.12.49, 6.16.9, 6.17
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Not affected: 1 product
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-02 Threatist record created from CVE-2025-39931
- 2026-10-03 Alias added: GHSA-rfcq-q5wv-mpcg
- 2026-10-16 CISA SSVC decision points changed
References
Patch 5
- https://git.kernel.org/stable/c/6241b9e2809b12da9130894cf5beddf088dc1b8a
- https://git.kernel.org/stable/c/2374c11189ef704a3e4863646369f1b8e6a27d71
- https://git.kernel.org/stable/c/24c1106504c625fabd3b7229611af617b4c27ac7
- https://git.kernel.org/stable/c/045ee26aa3920a47ec46d7fcb302420bf01fd753
- https://git.kernel.org/stable/c/9574b2330dbd2b5459b74d3b5e9619d39299fc6f
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2025-39931 · CVE Program
- CVE-2025-39931 · NVD
- FIRST EPSS
- GHSA-rfcq-q5wv-mpcg · GitHub Advisory Database · CC BY 4.0
- CVE-2025-39931 · Red Hat security data · CC BY 4.0
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