CVE-2026-46090: ALSA: aloop: Fix peer runtime UAF during format-change stop
Vulnerability summary
CVE-2026-46090 is a high (CVSS 7.8) Use After Free vulnerability in linux. EPSS estimates a 0.10% chance of exploitation in the next 30 days, higher than 0.9% of scored vulnerabilities.
Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 59 · Related 45Timeline
- 27-05-2026PublishedVulnerability first disclosed.
- 19-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: ALSA: aloop: Fix peer runtime UAF during format-change stop loopback_check_format() may stop the capture side when playback starts with parameters that no longer match a running capture stream. Commit 826af7fa62e3 ("ALSA: aloop: Fix racy access at PCM trigger") moved the peer lookup under cable->lock, but the actual snd_pcm_stop() still runs after dropping that lock. A concurrent close can clear the capture entry from cable->streams[] and detach or free its runtime while the playback trigger path still holds a stale peer substream pointer. Keep a per-cable count of in-flight peer stops before dropping cable->lock, and make free_cable() wait for those stops before detaching the runtime. This preserves the existing behavior while making the peer runtime lifetime explicit.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.0HighCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:HDiffers
- OSV · DebianEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- NVDNIST7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.10%
Chance of exploitation in the next 30 days
Percentile
1%
Versus all other CVEs
30-day change
Decrease -0.04 pp
From 0.14% 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 cause- CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
- CWE-364Signal Handler Race ConditionThe product uses a signal handler that introduces a race condition.
Affected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu159 products
- linuxAll versions (No fix recorded) | < 5.15.0-198.208 | < 6.8.0-136.136 | < 7.0.0-27.27
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 5.15.0-1117.124 | < 6.8.0-1061.64 | < 7.0.0-1008.8
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 597603d615d2b19a9e451d8cfac24372856a522d, < 83bd62fa9620ac98d5d694bde14c50f98c8e7189 | ≥ 597603d615d2b19a9e451d8cfac24372856a522d, < 345c24b2bcf0923dfae1ab41497351c68214ff76 | ≥ 597603d615d2b19a9e451d8cfac24372856a522d, < 3727a3541788412c393eec236ad228d72efe19c7 | ≥ 597603d615d2b19a9e451d8cfac24372856a522d, < d258cdce50ff3e02392917258e81a0ce9555c327 | ≥ 597603d615d2b19a9e451d8cfac24372856a522d, < 03f52a9c170431e8f10e156b9dc0dae80b3e9198 | ≥ 597603d615d2b19a9e451d8cfac24372856a522d, < bdd9503c3d222d2735b56c7a8b4422ccf3de6e5c | ≥ 597603d615d2b19a9e451d8cfac24372856a522d, < 5d45e34bf001344e2966dabca1897561bbc9e913 | ≥ 597603d615d2b19a9e451d8cfac24372856a522d, < e5c33cdc6f402eab8abd36ecf436b22c9d3a8aff | 2.6.37
- linux_kernel≥ 2.6.37, < 5.10.259 | ≥ 5.11, < 5.15.210 | ≥ 5.16, < 6.12.88 | ≥ 6.13, < 6.18.27 | ≥ 6.19, < 7.0.4 | 7.1:rc1
Debian1 product
- linuxAll versions (No fix recorded) | < 6.1.190-1 | < 6.12.88-1 | < 7.0.4-1
3 vendors · 162 products
