CVE-2025-37776: ksmbd: fix use-after-free in smb_break_all_levII_oplock()
Vulnerability summary
CVE-2025-37776 is a high (CVSS 8.8) Use After Free vulnerability in linux. EPSS estimates a 0.36% chance of exploitation in the next 30 days, higher than 29.8% of scored vulnerabilities.
Not severe (CVSS 8.8, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 4 · Related 4Timeline
- 01-05-2025PublishedVulnerability first disclosed.
- 05-08-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in smb_break_all_levII_oplock() There is a room in smb_break_all_levII_oplock that can cause racy issues when unlocking in the middle of the loop. This patch use read lock to protect whole loop.
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.0HighCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:HDiffers
- NVDNIST7.0HighCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:HDiffers
EPSS trend
Probability
0.36%
Chance of exploitation in the next 30 days
Percentile
30%
Versus all other CVEs
30-day change
Increase +0.01 pp
From 0.35% 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 causeAffected systems
Known conditions: network-reachable, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu129 products
- linuxAll versions (No fix recorded)
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded)
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 0626e6641f6b467447c81dd7678a69c66f7746cf, < 296cb5457cc6f4a754c4ae29855f8a253d52bcc6 | ≥ 0626e6641f6b467447c81dd7678a69c66f7746cf, < d54ab1520d43e95f9b2e22d7a05fc9614192e5a5 | ≥ 0626e6641f6b467447c81dd7678a69c66f7746cf, < d73686367ad68534257cd88a36ca3c52cb8b81d8 | ≥ 0626e6641f6b467447c81dd7678a69c66f7746cf, < 18b4fac5ef17f77fed9417d22210ceafd6525fc7 | 5.15
- linux_kernel≥ 5.15, < 6.6.88 | ≥ 6.7, < 6.12.25 | ≥ 6.13, < 6.14.4 | 6.15:rc1 | 6.15:rc2
Debian1 product
- linuxAll versions (No fix recorded) | < 6.12.25-1
3 vendors · 132 products
