CVE-2025-15514
Null Pointer Dereference in Ollama Image Processing Causes DoS
Publication date: 2026-01-12
Last updated on: 2026-01-12
Assigner: VulnCheck
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| ollama | ollama | to 0.13.5 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-395 | Catching NullPointerException should not be used as an alternative to programmatic checks to prevent dereferencing a null pointer. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability is a null pointer dereference in Ollama versions 0.11.5-rc0 through 0.13.5 affecting the multi-modal model image processing functionality. When the application processes base64-encoded image data via the /api/chat endpoint, it does not verify if the decoded data is valid media before passing it to the function mtmd_helper_bitmap_init_from_buf. This function can return NULL for malformed input, but the code does not check for this before dereferencing the pointer, leading to a crash. [2]
How can this vulnerability impact me? :
A remote attacker can exploit this vulnerability by sending specially crafted base64 image data that decodes to invalid media, causing a segmentation fault that crashes the runner process. This results in a denial of service (DoS) condition where the model becomes unavailable to all users until the service is restarted. [2]
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability can be detected by monitoring for crashes or segmentation faults in the Ollama runner process, especially after receiving base64-encoded image data via the /api/chat endpoint. Network detection could involve inspecting traffic for suspicious or malformed base64 image data sent to the /api/chat endpoint. Specific commands are not provided in the resources. [2]
What immediate steps should I take to mitigate this vulnerability?
Immediate mitigation steps include restarting the Ollama service if it crashes due to this vulnerability. Additionally, restricting or validating input to the /api/chat endpoint to prevent malformed base64 image data from being processed can help reduce risk. Since the vulnerability remains unresolved as of the advisory date, monitoring for updates or patches from Ollama is recommended. [2]