Unrated

Use-After-Free RCE in llama.cpp RPC GRAPH_RECOMPUTE Handler

IdentifiersCVE-2026-39909CWE-416· Use After Free

CVE-2026-39909 is a use-after-free vulnerability in llama.cpp affecting versions before b8585. The flaw resides in the RPC server's GRAPH_RECOMPUTE handler, where a previously stored computation graph can be re-executed after buffers referenced by that graph have already been freed. If the freed memory is subsequently reclaimed with attacker-controlled content, the stale references become dangling pointers that are dereferenced during graph recomputation. This memory corruption condition can be triggered remotely through crafted RPC requests and can be leveraged by an unauthenticated attacker to obtain arbitrary read and write primitives, which can then be escalated to full remote code execution. The issue does not require user interaction.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation can give a remote unauthenticated attacker arbitrary memory read and write capabilities within the vulnerable llama.cpp process. In practice, this can lead to full remote code execution and complete compromise of the affected service, with high impact to confidentiality, integrity, and availability.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, reduce exposure of the RPC server by restricting network access to trusted hosts only, disabling or isolating the RPC service where feasible, and preventing unauthenticated access through segmentation, firewall policy, or equivalent access controls. Because the flaw is remotely reachable and does not require user interaction, mitigation should focus on eliminating untrusted access to the vulnerable RPC interface until the upgrade can be completed.

Remediation

Patch, then assume compromise.

Upgrade llama.cpp to version b8585 or later, which is identified as containing the fix for this vulnerability. Ensure deployments are rebuilt and restarted with the patched version so the vulnerable RPC server code path is no longer exposed.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

GgerganovLlama.Cppapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

10 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

10 SOURCESView more in app

cvefeed high severityNews

Aug 21, 2026

CVE-2026-39909 - llama.cpp Use-After-Free in RPC GRAPH_RECOMPUTE Handler

A use-after-free vulnerability in llama.cpp's RPC server GRAPH_RECOMPUTE handler that can allow unauthenticated remote arbitrary read/write and full remote code execution.

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Exposure mapping

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Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity9