CVE-2026-31602: linux
Vulnerability summary
CVE-2026-31602 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% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 41 · Related 42Timeline
- 24-04-2026PublishedVulnerability first disclosed.
- 05-08-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: ALSA: ctxfi: Limit PTP to a single page Commit 391e69143d0a increased CT_PTP_NUM from 1 to 4 to support 256 playback streams, but the additional pages are not used by the card correctly. The CT20K2 hardware already has multiple VMEM_PTPAL registers, but using them separately would require refactoring the entire virtual memory allocation logic. ct_vm_map() always uses PTEs in vm->ptp[0].area regardless of CT_PTP_NUM. On AMD64 systems, a single PTP covers 512 PTEs (2M). When aggregate memory allocations exceed this limit, ct_vm_map() tries to access beyond the allocated space and causes a page fault: BUG: unable to handle page fault for address: ffffd4ae8a10a000 Oops: Oops: 0002 [#1] SMP PTI RIP: 0010:ct_vm_map+0x17c/0x280 [snd_ctxfi] Call Trace: atc_pcm_playback_prepare+0x225/0x3b0 ct_pcm_playback_prepare+0x38/0x60 snd_pcm_do_prepare+0x2f/0x50 snd_pcm_action_single+0x36/0x90 snd_pcm_action_nonatomic+0xbf/0xd0 snd_pcm_ioctl+0x28/0x40 __x64_sys_ioctl+0x97/0xe0 do_syscall_64+0x81/0x610 entry_SYSCALL_64_after_hwframe+0x76/0x7e Revert CT_PTP_NUM to 1. The 256 SRC_RESOURCE_NUM and playback_count remain unchanged.
CVSS metrics
6 scores · 5 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · ChainguardEcosystem 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
0.18%
Chance of exploitation in the next 30 days
Percentile
7%
Versus all other CVEs
30-day change
+0.05 pp
From 0.13% on 21-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Ubuntu158 products
- linuxAll versions (No fix recorded) | < 5.15.0-186.196 | < 6.8.0-136.136 | < 7.0.0-27.27
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 5.15.0-1112.119 | < 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)
Chainguard9 products
- linux-aws-6.12< 6.12.85-r0
- linux-aws-6.18< 6.18.31-r0
- linux-azure-6.18< 6.18.31-r0
- linux-gcp-6.18< 6.18.31-r0
- linux-qemu-6.12< 6.12.85-r0
Linux2 products
- linux≥ 391e69143d0a05f960e3ab39a8c26b7b230bb8a9, < c5908160e17cb56e1f61fbaee08adc21083f4933 | ≥ 391e69143d0a05f960e3ab39a8c26b7b230bb8a9, < de8016fb0904d68ac886e375069535996baa42ee | ≥ 391e69143d0a05f960e3ab39a8c26b7b230bb8a9, < 2b4331c08c0b385598b4d8ccd71e93ab3f4b2578 | ≥ 391e69143d0a05f960e3ab39a8c26b7b230bb8a9, < 452894005b4abe141b11fe01e7bfe152e6d3860f | ≥ 391e69143d0a05f960e3ab39a8c26b7b230bb8a9, < 365c36e1a126c6aa1aecedd3a351bcabc66f0c29 | ≥ 391e69143d0a05f960e3ab39a8c26b7b230bb8a9, < 3fd0685d7fef68c2d8a04876bcf9eaa0724ad6a5 | ≥ 391e69143d0a05f960e3ab39a8c26b7b230bb8a9, < b7f5ecd13cce8c2f8fa5a84c9aab65997142577e | ≥ 391e69143d0a05f960e3ab39a8c26b7b230bb8a9, < ad9011a795407093dcf507f6e5da1828987b4b47 | ≥ 391e69143d0a05f960e3ab39a8c26b7b230bb8a9, < e9418da50d9e5c496c22fe392e4ad74c038a94eb | 3.2
- linux_kernel≥ 3.2, < 6.6.136 | ≥ 6.7, < 6.12.83 | ≥ 6.13, < 6.18.24 | ≥ 6.19, < 6.19.14 | ≥ 7.0, < 7.0.1
Debian1 product
- linux< 6.1.176-1 | < 6.12.85-1 | < 6.19.14-1
4 vendors · 170 products
