CVE-2026-99059 — wireguard: noise: reject response consumption after intermediate initiation
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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.4% (30-day exploitation probability)+6
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
≥ e7096c131e5161fa3b8e52a650d7719d2857adfd and < fb5ce4c7790c3eeec820302d08d70ecf46af4295≥ e7096c131e5161fa3b8e52a650d7719d2857adfd and < c76a80db593096edf2b3b3972f58b6342a8c6c04≥ e7096c131e5161fa3b8e52a650d7719d2857adfd and < 4d64a3d6e96aa78619c9c29ffde309794974588a≥ e7096c131e5161fa3b8e52a650d7719d2857adfd and < 3bec3d32c2a3afd164fc87f95457df2cf9049c20≥ e7096c131e5161fa3b8e52a650d7719d2857adfd and < d0305f8d90029556260c6824b61c493c424eba9eversion 5.6≥ e7096c131e5161fa3b8e52a650d7719d2857adfd and < dbd1e21f4301bd2157cd771255f1ca6ba1c8a1f9≥ e7096c131e5161fa3b8e52a650d7719d2857adfd and < f4012ec25a4abb6a23dc40043f61e2d9a7deca6d and 1 more≥ e7096c131e5161fa3b8e52a650d7719d2857adfd and < 6b5b14cb5421e84191e3f6b5a7566783a402ff7f |
Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.7 | CVSS 3.1 | High | 2.2 | 5.5 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database |
| 7.7 | CVSS 3.1 | High | — | — | GitHub, Inc. via GitHub Security Advisories |
| 7.7 | CVSS 3.1 | High | — | — | Linux via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67) EPSS over time FIRST
Oct 24, 2026 → Oct 30, 2026 · 7 reading(s) · max 0.44%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- CVSS changed · 7.7
- Record published
- Affected products added · linux/linux
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 3× References added · Oct 23, 2026 – Oct 30, 2026
- 1× Official description updated · Oct 23, 2026 – Oct 23, 2026
References
10 on the record
- git.kernel.org/stable/c/d0305f8d90029556260c6824b61c493c424eba9e
- git.kernel.org/stable/c/6b5b14cb5421e84191e3f6b5a7566783a402ff7f
- git.kernel.org/stable/c/fb5ce4c7790c3eeec820302d08d70ecf46af4295
- nvd.nist.gov/vuln/detail/CVE-2026-99059
- git.kernel.org/stable/c/c76a80db593096edf2b3b3972f58b6342a8c6c04
- git.kernel.org/stable/c/f4012ec25a4abb6a23dc40043f61e2d9a7deca6d
- git.kernel.org/stable/c/4d64a3d6e96aa78619c9c29ffde309794974588a
- git.kernel.org/stable/c/3bec3d32c2a3afd164fc87f95457df2cf9049c20
- git.kernel.org/stable/c/dbd1e21f4301bd2157cd771255f1ca6ba1c8a1f9
- github.com/advisories/GHSA-c2jq-9mfv-9wqh
Elsewhere on this site
Related CVEs (same products)
- Unknown CVE-2026-99216 Drivers: hv: Don't reset VMBus connection state on error/exit paths 2d
- Unknown CVE-2026-99215 power: supply: core: prevent unregistering a power supply while a callback runs 2d
- Unknown CVE-2026-99207 scsi: target: Disable interrupts while holding delayed_cmd_lock 2d
- Unknown CVE-2026-99208 drm/xe/oa: Zero OA buffer at allocation 2d
- Unknown CVE-2026-99209 drm/xe: skip eviction of a BO with no resource 2d
- Unknown CVE-2026-99210 accel/rocket: clear rdev on device init failure 2d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-99059 is "wireguard: noise: reject response consumption after intermediate initiation", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.7 describes technical severity. EPSS 0.44% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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