---
id: CVE-2026-62943
title: btrbk is a tool for creating snapshots and remote backups of Btrfs subvolumes
summary: >-
  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 c…
severity: high
cvss: 8.7
cvssVector: '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'
cwe:
  - CWE-78
vendor: digint
product: btrbk
affected:
  - 'btrbk >= 0.29.0, < 0.32.7'
published: '2026-09-18'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T21:25:27.050'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-62943'
references:
  - url: >-
      https://github.com/digint/btrbk/commit/29ca3c093205395bdeb9dd98677ab4139c458aec
    label: security-advisories@github.com
  - url: 'https://github.com/digint/btrbk/releases/tag/v0.32.7'
    label: security-advisories@github.com
  - url: 'https://github.com/digint/btrbk/security/advisories/GHSA-pf45-7g54-65h5'
    label: security-advisories@github.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-62943.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-62943'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-62943'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00496
epssPercentile: 0.39999
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-18T19:24:36.668834Z'
cvssSource: cna
scores:
  cna: 8.7
  vendor: 8.8
ingestedAt: '2026-09-18T16:45:41.407Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · updated 2026-09-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-62943.json)