Live › vulnerability › CVE-2026-99059
Go to dashboardA race in the Linux kernel's WireGuard noise handshake lets a duplicated handshake response be consumed after a newer initiation has already run, so two threads can derive the same session. The sources do not say what an attacker gains beyond a reused session state.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-23 21:57 UTC. All times on this page are UTC.
Systems running a Linux kernel with WireGuard enabled, whether built in or loaded as a module, are in scope. The sources describe a timing race that requires duplicate handshake responses, and say it is very hard to hit in practice. Systems without WireGuard can skip it.
No product ranges from the sources yet.
uname -r and compare against the fixed kernel builds listed by your distributionlsmod | grep wireguard or modinfo wireguard to confirm WireGuard is loaded or built inEach row is the first time that source carried this signal. The analyst’s rows are its own findings.
In the Linux kernel, the following vulnerability has been resolved:
wireguard: noise: reject response consumption after intermediate initiation
Two threads begin processing the identical response message, received twice. The first thread, A, runs. While it's running, the second one, B, gets partway through, and during that slow calculation, or even while blocking on down_write(), A completes and then also a handshake initiation that's already been queued up runs in thread C, which itself takes that same down_write(). The handshake initiation creation succeeds, and sets the state back to waiting-for-response, and calls up_write(), at which point thread B resumes, because either its finished its calculations or was finally allowed to acquire down_write(). Thread B then copies the state back to the peer, and begins a new session, using that state, which is the same session as the one made in thread A.
Thread A Thread B Thread C
down_read() sA = handshake->state memcpy(cA, handshake->crypto) up_read() if (sA != 1) goto fail slow_crypto(cA) down_read() sB = handshake->state memcpy(cB, handshake->crypto) up_read() if (sB != 1) goto fail slow_crypto(cB) down_write() if (sA != handshake->state) goto fail memcpy(handshake->crypto, cA) handshake->state = 2 up_write() down_write() if (handshake->state != 2) goto fail derive_session(handshake->crypto) up_write() down_write() slow_crypto(handshake->crypto) handshake->state = 1 up_write() down_write() if (sB != handshake->state) goto fail memcpy(handshake->crypto, cB) handshake->state = 2 up_write() down_write() if (handshake->state != 2) goto fail derive_session(handshake->crypto) up_write()
This seems basically impossible to hit in a meaningful way in practice, but ensure that it absolutely cannot happen by comparing the ephemeral private key that's on the stack with the latest one that the peer's handshake state has.
This page as .md · .json · in your agent: get_signal("CVE-2026-99059")
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