CVE-2026-56101
OpenBSD ieee80211_crypto_tkip.c TKIP MIC Countermeasure Logic Inversion DoS
- State
- Published
- Severity
- 6.0 Medium
- Published
- Sep 8, 2026
- Updated
- Oct 27, 2026
- Reserved
- Jun 18, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 6.0 Medium | CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 5.3 Medium | CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H | VulnCheck |
Weaknesses
- CWE-697 Incorrect Comparison
Affected Products
| Product | Versions |
|---|---|
OpenBSDOpenBSD |
|
References
- Argus Systems Advisorytechnical-descriptionexploit
- Patch Commitpatch
- https://www.vulncheck.com/advisories/openbsd-ieee80211-crypto-tkip-c-tkip-mic-countermeasure-logic-inversion-dosthird-party-advisory
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