CVE-2026-39909

Received
Published: 21 Aug 2026, 16:28
Last modified:21 Aug 2026, 16:28

Vulnerability Summary

Overall Risk (default)
high
70/100
CVSS Score
9.2 CRITICAL
v4.0 (cve.org)
EPSS Score
No data
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

21 Aug 2026, 16:28
Published
Vulnerability first disclosed

Description

llama.cpp before b8585 contains a use-after-free vulnerability in the RPC server's GRAPH_RECOMPUTE handler that allows unauthenticated remote attackers to achieve arbitrary read and write access by storing a computation graph, freeing referenced buffers, and reclaiming freed memory with attacker-controlled content. Attackers can send RPC requests to trigger re-execution of stored graphs with dangling pointers, enabling full remote code execution without requiring authentication or user interaction.

CVSS Metrics

  • v4.0•CRITICAL•Score: 9.2CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
  • v4.0•CRITICAL•Score: 9.2CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
  • v3.1•HIGH•Score: 8.1CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Techniques & Countermeasures

  • CWE-416•Use After Free

    The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected Systems

  • ggml-org•llama.cpp

    < b8585

References (4)