CVE-2026-56101 json
OpenBSD ieee80211_crypto_tkip.c TKIP MIC Countermeasure Logic Inversion DoS
published 2026-09-08 2 mo ago modified 2026-10-27 13 d ago also EUVD-2026-72935
- cvss
- 5.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.6%
- EPSS 0.6% chance of exploitation in 30 days, percentile 49%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 59 d ago
Exploit prediction
0.60% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- pop.argus-systems.ai https://pop.argus-systems.ai/advisory/adv-209.html referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 6.0 | 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 |
| CNA | 3.1 | 5.3 | CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
| CNA | 4.0 | 6.0 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- OpenBSD OpenBSD
Classification
- Weakness
-
- CWE-697 Incorrect Comparison
References
-
github.com
/openbsd/src/commit/1ee99dfcc4ddc87afc6395d5d3094e9d2314fb5a
patch
-
pop.argus-systems.ai
/advisory/adv-209.html
technical-description, exploit
-
vulncheck.com
/advisories/openbsd-ieee80211-crypto-tkip-c-tkip-mic-countermeasure-logic-inversion-dos
third-party-advisory
Sources
- CVE List CVE-2026-56101
- NVD CVE-2026-56101
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