CVE-2026-87766
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.14%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- EPSS
- 0.14% probability · 4th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-59
- Source
- secalert@redhat.com
References
- https://access.redhat.com/security/cve/CVE-2026-87766
- https://bugs.debian.org/1145655
- https://bugzilla.redhat.com/show_bug.cgi?id=2530542
- https://github.com/containers/bubblewrap/releases/tag/v0.12.0
- https://github.com/containers/bubblewrap/security/advisories/GHSA-pxhw-h44j-8pfx
- https://www.openwall.com/lists/oss-security/2026/08/27/7
- http://www.openwall.com/lists/oss-security/2026/09/09/3
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.