Chipmaker Advanced Micro Devices on Wednesday pushed back on from Intel about a recently documented security flaw, saying its chips are mainly not affected.

AMD expects to publish security research on the flaw later on Wednesday but did provide an initial statement of its own:

To be clear, the security research team identified three variants targeting speculative execution. The threat and the response to the three variants differ by microprocessor company, and AMD is not susceptible to all three variants. Due to differences in AMD's architecture, we believe there is a near zero risk to AMD processors at this time.

AMD rose slightly after AMD issued the statement. The stock had fallen after Intel issued its statement earlier.

But Paul Kocher — security technology advisor at Rambus — said in an email to CNBC that AMD is indeed vulnerable to at least one of the threats discovered, the so-called "Spectre" vulnerability. Kocher was lead author on a paper that analyzed the vulnerabilities. (Kocher is also one of a group of researchers that discovered the vulnerability.)

On Tuesday the Register suggested that the flaw did not impact AMD's chips but instead primarily impacted chips from Intel. But Intel's public statement on Wednesday indicated that the flaw isn't restricted to Intel's CPUs. That said, Intel did indicate it's working with other companies, including AMD, to resolve the issue, and AMD's initial statement shows it is cooperating.

"As we typically do when a potential security issue is identified, AMD has been working across our ecosystem to evaluate and respond to the speculative execution attack identified by a security research team to ensure our users are protected," AMD said.

Intel CEO Brian Krzanich in a conversation with CNBC's Jon Fortt, saying that Google first informed Intel about the issue and that to Intel's knowledge the flaw had not been exploited.