Linux Kernel Out-of-Bounds Read Vulnerability
In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: Fix out of bounds reads when finding clock sources The current USB-audio driver code doesn't check bLength of each descriptor at traversing for clock…
Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.
Exploitation probability EPSS · FIRST
Exploitation signals 2 / 5
- KEV catalog (CISA)09 Apr 2025
- Exploited in EUVD (ENISA)09 Apr 2025
- Used by ransomwareno
- EPSS above 10 %1.4%
- No account, over the networkno
What to do
Fix
Apply the vendor’s fix as soon as it is available.
CISA guidance: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Meanwhile
Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.
Manufacturers (CRA)
Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained
Description ENISA EUVD
In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: Fix out of bounds reads when finding clock sources The current USB-audio driver code doesn't check bLength of each descriptor at traversing for clock descriptors. That is, when a device provides a bogus descriptor with a shorter bLength, the driver might hit out-of-bounds reads. For addressing it, this patch adds sanity checks to the validator functions for the clock descriptor traversal. When the descriptor length is shorter than expected, it's skipped in the loop. For the clock source and clock multiplier descriptors, we can just check bLength against the sizeof() of each descriptor type. OTOH, the clock selector descriptor of UAC2 and UAC3 has an array of bNrInPins elements and two more fields at its tail, hence those have to be checked in addition to the sizeof() check.
Affected products
- patch: 6.11.11
- b8e4f1fdfa422398c2d6c47bfb7d1feb3046d70a <ab011f7439d9bbfd34fd3b9cef4b2d6d952c9bb9
- b8e4f1fdfa422398c2d6c47bfb7d1feb3046d70a <74cb86e1006c5437b1d90084d22018da30fddc77
- patch: 5.15.174
- b8e4f1fdfa422398c2d6c47bfb7d1feb3046d70a <ea0fa76f61cf8e932d1d26e6193513230816e11d
- 5.3.11 <5.4
- patch: 6.6.64
- b8e4f1fdfa422398c2d6c47bfb7d1feb3046d70a <a3dd4d63eeb452cfb064a13862fb376ab108f6a6
- patch: 6.12.2
- patch: 6.1.120
- b8e4f1fdfa422398c2d6c47bfb7d1feb3046d70a <096bb5b43edf755bc4477e64004fa3a20539ec2f
- patch: 5.4.287
Open source packages OSV
Affected libraries according to OSV, with fixed versions.
Timeline
-
Published
-
Exploitation reported (ENISA)
-
Added to the KEV catalog
-
CISA remediation due date
References
Other exploited vulnerabilities from the same vendor
- CVE-2026-46300Linux Kernel Missing Initialization of a Variable Vulnerability5.4 · Rising fast
- CVE-2026-53266Linux Kernel Out-of-Bounds Write Vulnerability4.7 · Actively exploited
- CVE-2025-39964Linux Kernel Race Condition Vulnerability4.4 · Actively exploited
- CVE-2025-39682Linux Kernel Improper Check for Unusual or Exceptional Conditions Vulnerability5.8 · Actively exploited
- CVE-2026-53362Linux Kernel Unspecified Vulnerability4.3 · Actively exploited
- CVE-2022-0995Linux Kernel Out-of-Bounds Write Vulnerability4.6 · Actively exploited