Cve-2026-31507 — CraftedSignal Threat Feedhttps://feed.craftedsignal.io/tags/cve-2026-31507/Trending threats, MITRE ATT&CK coverage, and detection metadata — refreshed continuously.Hugoenhello@craftedsignal.iohello@craftedsignal.ioThu, 23 Apr 2026 07:27:47 +0000CVE-2026-31507 Double-Free Vulnerability in net/smchttps://feed.craftedsignal.io/briefs/2024-05-cve-2026-31507/Thu, 23 Apr 2026 07:27:47 +0000hello@craftedsignal.iohttps://feed.craftedsignal.io/briefs/2024-05-cve-2026-31507/CVE-2026-31507 is a double-free vulnerability in the net/smc module that occurs when the tee() function duplicates a splice pipe buffer, potentially leading to memory corruption and denial of service.On April 23, 2026, Microsoft published a security update guide addressing CVE-2026-31507, a double-free vulnerability residing in the net/smc (Sockets Multiplexing Controller) module of the Linux kernel. The vulnerability stems from a flaw in how the tee() function handles the duplication of splice pipe buffers. Specifically, when tee() duplicates a splice pipe buffer associated with the smc_spd_priv structure, it can lead to a double-free condition. This flaw could allow a local attacker to trigger memory corruption or a denial-of-service condition. While specific exploitation details are currently lacking, the nature of double-free vulnerabilities makes them a critical concern for system stability and security.

Attack Chain

  1. A local attacker gains access to the system.
  2. The attacker crafts a malicious program that interacts with the net/smc module.
  3. The program triggers the tee() function to duplicate a splice pipe buffer related to smc_spd_priv.
  4. Due to the vulnerability, the same memory region associated with smc_spd_priv is freed twice.
  5. The double-free corrupts the heap metadata.
  6. Subsequent memory allocations may lead to arbitrary code execution or denial-of-service.
  7. The attacker could leverage the memory corruption to escalate privileges.
  8. Successful exploitation results in system compromise.

Impact

Successful exploitation of CVE-2026-31507 can lead to memory corruption, potentially enabling arbitrary code execution and privilege escalation. A more likely outcome is a denial-of-service condition, where the system becomes unstable or crashes due to heap corruption. The vulnerability affects systems utilizing the affected net/smc module. While the number of potential victims is unknown, the wide deployment of the Linux kernel makes this a significant concern.

Recommendation

  • Apply the security patch provided by Microsoft that addresses CVE-2026-31507 to mitigate the double-free vulnerability.
  • Monitor systems for unusual tee() function calls within the net/smc module using a process creation rule with relevant command-line arguments and process ancestry.
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