What is CVE-2019-20427?

CVE-2019-20427 is a critical-severity vulnerability in Lustre, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.8/10. Published 2020-01-27.

How severe is CVE-2019-20427?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Buffer overflow in Lustre

CVE-2019-20427

In the Lustre file system before 2.12.3, the ptlrpc module has a buffer overflow and panic, and possibly remote code execution, due to the lack of validation for specific fields of packets sent by a client. Interaction between req_capsule_get_size and tgt_brw_write leads to a tgt_shortio2pages integer signedness error.

Vulnerability class: Buffer Overflow

Published 2020-01-27 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.051 (92.1th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 92nd percentile — 92.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.049 · newest: 0.051 · change: +0.002

Affected products

Lustre

Weakness classification (CWE)

CWE-120 — Buffer Copy without Checking Size of Input (Classic Buffer Overflow)

References

wiki.lustre.org/Lustre_2.12.3_Changelog (Release Notes, Vendor Advisory)
lustre.org/ (Product, Vendor Advisory)
jira.whamcloud.com/browse/LU-12600 (Exploit, Third Party Advisory, Issue Tracking)
review.whamcloud.com/ (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2019-20427?: CVE-2019-20427 is a critical-severity vulnerability in Lustre, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.8/10. Published 2020-01-27.
How severe is CVE-2019-20427?: Critical severity. CVSS v3 base score is 9.8 out of 10.