Kernel memory corruption via oversized PCM packets
Published Dec 6, 2025 · Updated Aug 5, 2026
Buffer overflow in the Linux ALSA USB-audio driver allows local users to corrupt kernel memory through crafted PCM parameters and playback. The endpoint setup derives URB packet sizes from the stream rate and packets per second without rejecting values above the descriptor-derived maxpacksize. Access to an ALSA PCM device backed by a USB audio endpoint is required; an oversized transfer can disclose or overwrite adjacent kernel memory or crash the host.
Summary
What happened
Buffer overflow in the Linux ALSA USB-audio driver allows local users to corrupt kernel memory through crafted PCM parameters and playback. The endpoint setup derives URB packet sizes from the stream rate and packets per second without rejecting values above the descriptor-derived maxpacksize. Access to an ALSA PCM device backed by a USB audio endpoint is required; an oversized transfer can disclose or overwrite adjacent kernel memory or crash the host.
The record
- CVE
- CVE-2025-40269
- Published
- Dec 6, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Dec 6, 2025CVE publishedPublication date reported by the CVE source.
- Aug 5, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=02c56650f3c118d3752122996d96173d26bb13aa <480a1490c595a242f27493a4544b3efb21b29f6a
- Affected versionversion=2d50acd7dbd0682a56968ad9551341d7fc5b6eaf <c4dc012b027c9eb101583011089dea14d744e314
- Affected versionversion=4.14.186 <4.14.188
- Affected versionversion=4.19.130 <4.19.132
- Affected versionversion=4.4.229 <4.4.230
- Affected versionversion=4.9.229 <4.9.230
- Affected versionversion=5.4.49 <5.4.51
- Affected versionversion=5.7.6 <5.7.8
- Affected versionversion=5.8
- Affected versionversion=5ef30e443e6d3654cccecec99cf481a69a0a6d3b <ab0b5e92fc36ee82c1bd01fe896d0f775ed5de41
- Affected versionversion=99703c921864a318e3e8aae74fde071b1ff35bea <282aba56713bbc58155716b55ca7222b2d9cf3c8
- Affected versionversion=aba41867dd66939d336fdf604e4d73b805d8039f <e0ed5a36fb3ab9e7b9ee45cd17f09f6d5f594360
- Affected versionversion=d288dc74f8cf95cb7ae0aaf245b7128627a49bf3 <d67dde02049e632ba58d3c44a164a74b6a737154
- Affected versionversion=f0bd62b64016508938df9babe47f65c2c727d25c <05a1fc5efdd8560f34a3af39c9cf1e1526cc3ddf
- Affected versionversion=f0bd62b64016508938df9babe47f65c2c727d25c <217d47255a2ec8b246f2725f5db9ac3f1d4109d7
- Affected versionversion=f0bd62b64016508938df9babe47f65c2c727d25c <6a5da3fa80affc948923f20a4e086177f505e86e
- Affected versionversion=f0bd62b64016508938df9babe47f65c2c727d25c <98e9d5e33bda8db875cc1a4fe99c192658e45ab6
- Affected versionversion=f0bd62b64016508938df9babe47f65c2c727d25c <d2c04f20ccc6c0d219e6d3038bab45bc66a178ad
- Affected versionversion=f0bd62b64016508938df9babe47f65c2c727d25c <ece3b981bb6620e47fac826a2156c090b1a936a0
- Affected versionversion=f0bd62b64016508938df9babe47f65c2c727d25c <ef592bf2232a2daa9fffa8881881fc9957ea56e9
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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