CVE-2026-56101: OpenBSD · Incorrect Comparison
Affects OpenBSDSource CVE Database V5
Public exploit available · CVSS 6.0 Medium : upgrade to 1ee99dfcc4ddc87afc6395d5d3094e9d2314fb5a as a priority.
Data as of 27 Oct 2026, 10:27 UTC
- CISA SSVC
- Exploitation
- Proof of concept is public or traded
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-09-10.
- Patch
- Available – fixed in 1ee99dfcc4ddc87afc6395d5d3094e9d2314fb5a
CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 8 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
CISA SSVC: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by VulnCheck
, 82 days before disclosure
CVE published
on cve.org
, t = 0
CISA SSVC assessment
proof of concept public
, 46 hours after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA SSVC, the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade OpenBSD to 1ee99dfcc4ddc87afc6395d5d3094e9d2314fb5a.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| OpenBSDOpenBSD | Affected
| Fixed in
|
GitHubOpenBSDpkg:github/OpenBSDOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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.