CVE-2026-87766
HighCVSS 8.8Exploitation Probability (EPSS)
Low risk4th percentile - higher than 4% of all known CVEs
Summary
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. Fixed in bubblewrap 0.12.0.
Risk Assessment
An attacker could write files outside the sandbox, potentially leading to system integrity compromise or privilege escalation.
Recommendation
Update bubblewrap to version 0.12.0 or later, which includes the fix.
Other vulnerabilities in bubblewrap
See all- CVE-2016-8659High
Bubblewrap before 0.1.3 sets the PR_SET_DUMPABLE flag, which might allow local users to gain privileges by attaching to the process, as demonstrated by sending commands to a PrivSep socket.
- CVE-2017-5226Critical
CVE-2017-5226 allows a nonprivileged session to escape the bubblewrap sandbox by using the TIOCSTI ioctl to push characters into the terminal's input buffer.
- CVE-2026-41163High
bubblewrap is a low-level unprivileged sandboxing tool. From version 0.11.0 to before version 0.11.2, if bubblewrap is installed in setuid mode then the user can use ptrace to attach to bubblewrap and control the unprivileged part of the sandbox setup phase. This allows the attacker to arbitrarily use the privileged operations, and in particular the "overlay mount" operation, allowing the creation of overlay mounts which is otherwise not allowed in the setuid version of bubblewrap. This issue has been patched in version 0.11.2.
Original NVD description (English source)
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.