CVE-2021-31829

Name: CVE-2021-31829
Creator: NVD / NIST
Published: 2021-05-06T16:15:07.493+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.5/10EPSS 0.31%

Last modified Jun 17, 2026

CVE-2021-31829 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. kernel/bpf/verifier.c in the Linux kernel through 5.12.1 performs undesirable speculative loads, leading to disclosure of stack content via side-channel attacks, aka CID-801c6058d14a. The specific concern is not protecting the BPF stack area against speculative loads. EPSS estimates a 0.31% chance of exploitation in the next 30 days.

Description

kernel/bpf/verifier.c in the Linux kernel through 5.12.1 performs undesirable speculative loads, leading to disclosure of stack content via side-channel attacks, aka CID-801c6058d14a. The specific concern is not protecting the BPF stack area against speculative loads. Also, the BPF stack can contain uninitialized data that might represent sensitive information previously operated on by the kernel.

Metrics

CVSS 3.1

5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS Probability

0.31%

22.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-863

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	<= 5.12.1
Fedoraproject	Fedora	32
Fedoraproject	Fedora	33
Fedoraproject	Fedora	34
Debian	Debian Linux	9.0

References

http://www.openwall.com/lists/oss-security/2021/05/04/4Mailing List, Patch, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/05/04/4Mailing List, Patch, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/05/04/4Mailing List, Patch, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/05/04/4Mailing List, Patch, Third Party Advisory
https://github.com/torvalds/linux/commit/801c6058d14a82179a7ee17a4b532cac6fad067fPatch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/06/msg00019.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VWCZ6LJLENL2C3URW5ICARTACXPFCFN2/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Y4X2G5YAPYJGI3PFEZZNOTRYI33GOCCZ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZI7OBCJQDNWMKLBP6MZ5NV4EUTDAMX6Q/
http://www.openwall.com/lists/oss-security/2021/05/04/4Mailing List, Patch, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/05/04/4Mailing List, Patch, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/05/04/4Mailing List, Patch, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/05/04/4Mailing List, Patch, Third Party Advisory
https://github.com/torvalds/linux/commit/801c6058d14a82179a7ee17a4b532cac6fad067fPatch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/06/msg00019.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VWCZ6LJLENL2C3URW5ICARTACXPFCFN2/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Y4X2G5YAPYJGI3PFEZZNOTRYI33GOCCZ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZI7OBCJQDNWMKLBP6MZ5NV4EUTDAMX6Q/

Timeline

Published: May 6, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-31829?

How severe is CVE-2021-31829?

CVE-2021-31829 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.31% probability of exploitation in the next 30 days.

How do I fix CVE-2021-31829?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-31829?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST