What is CVE-2026-58374?

CVE-2026-58374 is a medium-severity vulnerability in W1.fi Hostapd, classified under Off-by-one Error. CVSS score: 6.5/10. Published 2026-06-30.

How severe is CVE-2026-58374?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in W1.fi Hostapd

CVE-2026-58374

In hostapd before 2.12, a missing bounds check in AP-mode Wi-Fi 7 (IEEE 802.11be) Multi-Link Operation (MLO) association request processing allows an unauthenticated attacker within wireless range to send a crafted management frame containing a malformed Multi-Link Element or Per-STA Profile subelement. In hostapd_process_ml_assoc_req() in src/ap/ieee802_11_eht.c, the received link_id field can be parsed as value 15, but the corresponding links[] storage only has valid entries for lower link IDs (0 through 14). This causes an out-of-bounds write / small memory corruption during association processing before the 4-way handshake. The attack does not require network credentials, prior authentication, or user interaction. The confirmed practical impact is denial of service through hostapd process termination. This affects hostapd v2.11 and newer development snapshots before v2.12 when built with CONFIG_IEEE80211BE enabled. The issue is fixed in hostapd v2.12 and the upstream 2026-1 fixes.

Published 2026-06-30 · last modified 2026-07-02.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.005 (38.6th percentile), scored 2026-10-08.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 39th percentile — 38.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002

Affected products

W1.fi Hostapd — versions 0

Weakness classification (CWE)

CWE-193 — Off-by-one Error

References

git.w1.fi/cgit/hostap/commit/ (Patch, patch)
git.w1.fi/cgit/hostap/commit/ (Patch, patch)
w1.fi/security/2026-1/ (vendor-advisory, patch, Issue Tracking)
w1.fi/security/2026-1/missing-ml-parsing-validation.txt (vendor-advisory, Third Party Advisory, Mitigation)
www.openwall.com/lists/oss-security/2026/06/30/1 (Patch, Mailing List, Mitigation)

Frequently asked questions

What is CVE-2026-58374?: CVE-2026-58374 is a medium-severity vulnerability in W1.fi Hostapd, classified under Off-by-one Error. CVSS score: 6.5/10. Published 2026-06-30.
How severe is CVE-2026-58374?: Medium severity. CVSS v3 base score is 6.5 out of 10.