7.8

CVE-2025-40269: ALSA: usb-audio: Fix potential overflow of PCM transfer buffer

Deferred
AliasesUBUNTU-CVE-2025-40269DEBIAN-CVE-2025-40269
Published 06-12-2025Last modified 05-08-2026

Vulnerability summary

CVE-2025-40269 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 7.3% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.18%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 57 · Related 39
DLA-4404-1DLA-4436-1MGASA-2026-0017MGASA-2026-0018OPENSUSE-SU-2026:20145-1RHSA-2026:2212

Timeline

  1. 06-12-2025
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: Fix potential overflow of PCM transfer buffer The PCM stream data in USB-audio driver is transferred over USB URB packet buffers, and each packet size is determined dynamically. The packet sizes are limited by some factors such as wMaxPacketSize USB descriptor. OTOH, in the current code, the actually used packet sizes are determined only by the rate and the PPS, which may be bigger than the size limit above. This results in a buffer overflow, as reported by syzbot. Basically when the limit is smaller than the calculated packet size, it implies that something is wrong, most likely a weird USB descriptor. So the best option would be just to return an error at the parameter setup time before doing any further operations. This patch introduces such a sanity check, and returns -EINVAL when the packet size is greater than maxpacksize. The comparison with ep->packsize[1] alone should suffice since it's always equal or greater than ep->packsize[0].

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.18%

Chance of exploitation in the next 30 days

Percentile

7%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.18% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu153 products
  • linuxAll versions (No fix recorded) | < 5.15.0-173.183 | < 6.8.0-106.106 | < 6.17.0-14.14
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1103.110 | < 6.8.0-1050.53 | < 6.17.0-1007.7
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian1 product
  • linux< 6.1.159-1 | < 6.12.63-1 | < 6.17.9-1
Linux1 product
  • linux≥ 02c56650f3c118d3752122996d96173d26bb13aa, < 480a1490c595a242f27493a4544b3efb21b29f6a | ≥ 5ef30e443e6d3654cccecec99cf481a69a0a6d3b, < ab0b5e92fc36ee82c1bd01fe896d0f775ed5de41 | ≥ 99703c921864a318e3e8aae74fde071b1ff35bea, < 282aba56713bbc58155716b55ca7222b2d9cf3c8 | ≥ 2d50acd7dbd0682a56968ad9551341d7fc5b6eaf, < c4dc012b027c9eb101583011089dea14d744e314 | ≥ aba41867dd66939d336fdf604e4d73b805d8039f, < e0ed5a36fb3ab9e7b9ee45cd17f09f6d5f594360 | ≥ d288dc74f8cf95cb7ae0aaf245b7128627a49bf3, < d67dde02049e632ba58d3c44a164a74b6a737154 | ≥ f0bd62b64016508938df9babe47f65c2c727d25c, < 6a5da3fa80affc948923f20a4e086177f505e86e | ≥ f0bd62b64016508938df9babe47f65c2c727d25c, < 217d47255a2ec8b246f2725f5db9ac3f1d4109d7 | ≥ f0bd62b64016508938df9babe47f65c2c727d25c, < ef592bf2232a2daa9fffa8881881fc9957ea56e9 | ≥ f0bd62b64016508938df9babe47f65c2c727d25c, < ece3b981bb6620e47fac826a2156c090b1a936a0 | ≥ f0bd62b64016508938df9babe47f65c2c727d25c, < 98e9d5e33bda8db875cc1a4fe99c192658e45ab6 | ≥ f0bd62b64016508938df9babe47f65c2c727d25c, < d2c04f20ccc6c0d219e6d3038bab45bc66a178ad | ≥ f0bd62b64016508938df9babe47f65c2c727d25c, < 05a1fc5efdd8560f34a3af39c9cf1e1526cc3ddf | ≥ 4.4.229, < 4.4.230 | ≥ 4.9.229, < 4.9.230 | ≥ 4.14.186, < 4.14.188 | ≥ 4.19.130, < 4.19.132 | ≥ 5.4.49, < 5.4.51 | ≥ 5.7.6, < 5.7.8 | 5.8

3 vendors · 155 products

References

43 links
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