CVE-2026-64255: wifi: iwlwifi: mld: validate sta_mask before ffs() in BA session handlers
Vulnerability summary
CVE-2026-64255 is a high (CVSS 8.8) Out-of-bounds Read vulnerability in linux. EPSS estimates a 0.27% chance of exploitation in the next 30 days, higher than 19.7% of scored vulnerabilities.
Not severe (CVSS 8.8, adjacent network); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 14 · Related 12Timeline
- 24-07-2026PublishedVulnerability first disclosed.
- 19-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: wifi: iwlwifi: mld: validate sta_mask before ffs() in BA session handlers Three BA session handlers use ffs(ba_data->sta_mask) - 1 to derive a station ID without checking that sta_mask is non-zero. When sta_mask is zero, ffs() returns 0 and the subtraction wraps to 0xFFFFFFFF, causing an out-of-bounds access on fw_id_to_link_sta[]. Add WARN_ON_ONCE(!ba_data->sta_mask) guards before each ffs() call, consistent with the existing check in iwl_mld_ampdu_rx_start().
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated8.8HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated8.8HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- NVDNIST8.8HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.27%
Chance of exploitation in the next 30 days
Percentile
20%
Versus all other CVEs
30-day change
Increase +0.05 pp
From 0.22% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: adjacent network, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu142 products
- linuxAll versions (No fix recorded) | < 7.0.0-31.31
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 7.0.0-1012.12
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 9aa3856d9b6f3f8bf085b5bbb5f3703578bf452b, < 1de92789ce31e46fa7e7d8e89c90b19cdb1c103b | ≥ 9aa3856d9b6f3f8bf085b5bbb5f3703578bf452b, < fe7f339f63c9dc4ca546ed7ac38ba4bb3a99dcfc | ≥ 9aa3856d9b6f3f8bf085b5bbb5f3703578bf452b, < f056fc2b927448d37eca6b6cacc3d1b0f67b20d2 | 6.4
- linux_kernel≥ 6.4, < 6.18.38 | ≥ 6.19, < 7.1.3
Debian1 product
- linuxAll versions (No fix recorded) | < 7.1.3-1
3 vendors · 145 products
