CVE-2026-87766

Bubblewrap: bubblewrap: symlink traversal via /oldroot allows writing files outside sandbox during setup

CVE-2026-87766 is fixed in 3 products on 1 platform, first by RHSA-2026:85312, released September 9, 2026. It is not reported as exploited. Patch Radar priority: High.

High

CVSS

8.8

Important

Exploitation

None reported

No vendor assessment

CISA KEV

Not listed

Not in the Known Exploited Vulnerabilities catalog

EPSS

0.0021

11th percentile

A flaw was found in bubblewrap. During sandbox setup, creating files or directories under the new root can follow a parent symlink onto the host via /oldroot, writing attacker-chosen paths outside the sandbox as the launching user. This happens before the sandboxed process starts. This issue is GHSA-pxhw-h44j-8pfx. It is fixed in bubblewrap 0.12.0.

Where it's fixed

Product	Fixed in	Fix	Released
Linux
bubblewrap · Debian 13.5 (trixie)	0.12.0-1~deb13u1	DEBIAN-CVE-2026-87766	Sep 10, 2026
bubblewrap · Debian 14	0.12.0-1	DEBIAN-CVE-2026-87766	Sep 10, 2026
bubblewrap · RHEL 10	0.10.0-3.el10_0.4	RHSA-2026:85312	Sep 9, 2026
bubblewrap · RHEL 8	0:0.4.0-3.el8_10	RHSA-2026:85306	Oct 20, 2026
bubblewrap · RHEL 9	0:0.6.3-1.el9_8.1	RHSA-2026:85309	Oct 20, 2026
bubblewrap · almalinux 10	0.10.0-5.el10_2	ALSA-2026:85308	Nov 7, 2026
bubblewrap · almalinux 8	0.4.0-3.el8_10	ALSA-2026:85306	Nov 7, 2026
bubblewrap · almalinux 9	0.6.3-1.el9_8.1	ALSA-2026:85309	Nov 7, 2026
bubblewrap · amzn 2023	0.12.0-1.amzn2023.0.1	ALAS2023-2026-3105	Sep 28, 2026
bubblewrap · ol 10	0:0.10.0-5.el10_2	ELSA-2026-85308	Nov 7, 2026
bubblewrap · ol 8	0:0.4.0-3.el8_10	ELSA-2026-85306	Nov 7, 2026
bubblewrap · ol 9	0:0.6.3-1.el9_8.1	ELSA-2026-85309	Nov 7, 2026
bubblewrap · rocky 10	0:0.10.0-5.el10_2	RLSA-2026:85308	Nov 7, 2026
bubblewrap · rocky 8	0:0.4.0-3.el8_10	RLSA-2026:85306	Nov 7, 2026
bubblewrap · rocky 9	0:0.6.3-1.el9_8.1	RLSA-2026:85309	Nov 7, 2026
bubblewrap-debuginfo · amzn 2023	0.12.0-1.amzn2023.0.1	ALAS2023-2026-3105	Sep 28, 2026
bubblewrap-debugsource · amzn 2023	0.12.0-1.amzn2023.0.1	ALAS2023-2026-3105	Sep 28, 2026

Details

Published
September 9, 2026
Weakness
Improper Link Resolution Before File Access ('Link Following')
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Vendor advisory
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-87766

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