What is CVE-2011-4126?

CVE-2011-4126 is a high-severity vulnerability in Calibre-Ebook Calibre, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 8.1/10. Published 2021-10-27.

How severe is CVE-2011-4126?

High severity. CVSS v3 base score is 8.1 out of 10.

Vulnerability in Calibre-Ebook Calibre

CVE-2011-4126

Race condition issues were found in Calibre at devices/linux_mount_helper.c allowing unprivileged users the ability to mount any device to anywhere.

Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)

Published 2021-10-27 · last modified 2026-06-16.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.015 (73.9th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 74th percentile — 73.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.015 · newest: 0.015 · change: 0.000

Affected products

Calibre-Ebook Calibre
Calibre

Weakness classification (CWE)

CWE-367 — Time-of-check Time-of-use (TOCTOU) Race Condition

References

git.zx2c4.com/calibre-mount-helper-exploit/about/ (Exploit, Third Party Advisory)
www.openwall.com/lists/oss-security/2011/11/02/2 (Mailing List, Third Party Advisory)
bugs.launchpad.net/calibre/+bug/885027 (Exploit, Third Party Advisory, Issue Tracking)
lwn.net/Articles/464824/ (Third Party Advisory, Not Applicable)

Frequently asked questions

What is CVE-2011-4126?: CVE-2011-4126 is a high-severity vulnerability in Calibre-Ebook Calibre, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 8.1/10. Published 2021-10-27.
How severe is CVE-2011-4126?: High severity. CVSS v3 base score is 8.1 out of 10.