CVE-2021-26708: linux linux_kernel Improper Locking
Vulnerability summary
CVE-2021-26708 is a high (CVSS 7.0) Improper Locking vulnerability in linux linux_kernel. EPSS estimates a 1.60% chance of exploitation in the next 30 days, higher than 75.8% of scored vulnerabilities.
Not severe (CVSS 7, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 5 · Related 2Timeline
- 05-02-2021PublishedVulnerability first disclosed.
- 03-08-2024Last modifiedVulnerability information updated.
Description
A local privilege escalation was discovered in the Linux kernel before 5.10.13. Multiple race conditions in the AF_VSOCK implementation are caused by wrong locking in net/vmw_vsock/af_vsock.c. The race conditions were implicitly introduced in the commits that added VSOCK multi-transport support.
CVSS metrics
4 scores · 3 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated7.0HighCVSS:3.1/AV:L/AC:H/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:H
EPSS trend
Probability
1.60%
Chance of exploitation in the next 30 days
Percentile
76%
Versus all other CVEs
30-day change
No change 0.00 pp
From 1.60% 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: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu19 products
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.3All versions (No fix recorded)
- linux-azureAll versions (No fix recorded)
- linux-azure-5.3All versions (No fix recorded)
- linux-azure-edgeAll versions (No fix recorded)
Netapp8 products
- aff_baseboard_management_controllerna
- baseboard_management_controller_500f_firmware< 15.3
- baseboard_management_controller_a250_firmware< 15.3
- cloud_backupna
- fas_baseboard_management_controllerna
Mageia3 products
- kernel< 5.10.14-1.mga7
- kmod-virtualbox< 6.1.18-6.mga7
- kmod-xtables-addons< 3.13-12.mga7
Debian1 product
- linux< 5.10.13-1
Linux1 product
- linux_kernel≥ 5.5, < 5.10.13
5 vendors · 32 products
References
17 links- cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.13X Refsource MISCWEBREPORTRelease NotesVendor Advisory
- www.openwall.com/lists/oss-security/2021/02/04/5X Refsource MISCREPORTMailing ListPatchThird Party Advisory
- www.openwall.com/lists/oss-security/2021/02/05/6Mailing ListX Refsource MLISTREPORTPatchThird Party Advisory
