CVE-2026-56101OpenBSD ieee80211_crypto_tkip.c TKIP MIC Countermeasure Logic Inversion DoS
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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OpenBSD before commit 1ee99df contains an inverted comparison vulnerability in the ieee80211_michael_mic_failure() function within sys/net80211/ieee80211_crypto_tkip.c that allows unauthenticated attackers within RF range to trigger denial of service by sending two malformed TKIP frames separated by more than 60 seconds. Attackers can exploit the reversed TKIP MIC failure countermeasure window check to deauthenticate all associated TKIP stations and block reassociation for up to 90 seconds, while within-window MIC failures that should engage countermeasures are silently discarded, leaving key-recovery attempts undetected.
- CVSS
- 5.3 MEDIUM (v3.1, CNA)CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- CWE-697
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- VulnCheck
- NVD analysis
- Awaiting Analysis
- Record last updated
- Sep 10, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
OpenBSD OpenBSD openbsd:openbsd (from the name) | before 1ee99dfcc4ddc87afc6395d5d3094e9d2314fb5a | CNA record |
References
- https://pop.argus-systems.ai/advisory/adv-209.htmltechnical-description, exploit
- https://github.com/openbsd/src/commit/1ee99dfcc4ddc87afc6395d5d3094e9d2314fb5apatch
- https://www.vulncheck.com/advisories/openbsd-ieee80211-crypto-tkip-c-tkip-mic-countermeasure-logic-inversion-dosthird-party-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.