CVE-2026-62943

high

Description

btrbk is a tool for creating snapshots and remote backups of Btrfs subvolumes. From 0.29.0 until 0.32.7, btrbk's ssh_filter_btrbk.sh constructs allow_stream_match with a start anchor but without an end-of-string anchor for the complete command. A user restricted through an authorized_keys forced command can append a trailing pipe command after a valid btrbk command prefix, bypassing the allowlist and executing arbitrary commands with the privileges of the backup-target SSH account. Deployments that do not use ssh_filter_btrbk.sh in authorized_keys are not affected. This issue is fixed in version 0.32.7.

References

https://github.com/digint/btrbk/security/advisories/GHSA-pf45-7g54-65h5

https://github.com/digint/btrbk/releases/tag/v0.32.7

https://github.com/digint/btrbk/commit/29ca3c093205395bdeb9dd98677ab4139c458aec

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-83054

Details

Source: Mitre, NVD

Published: 2026-09-18

Updated: 2026-09-24

Risk Information

CVSS v2

Base Score: 9

Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:C

Severity: High

CVSS v3

Base Score: 8.8

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

Severity: High

CVSS v4

Base Score: 8.7

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Severity: High

EPSS

EPSS: 0.00496