CVE-2026-87766Bubblewrap: bubblewrap: symlink traversal via /oldroot allows writing files outside sandbox during setup
- 8.8HighCVSS base score
- 0.21%Exploitation in 30 daysEPSS · top 89% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By redhat
Published
- 2 months later
· 2 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| redhatCNA (assigner) | 3.1 | High8.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
| NVDNVD · Awaiting Analysis | 3.1 | High8.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.21% · top 89% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.8.
Affected products
Red Hat · Red Hat Enterprise Linux 10
- unaffected 0:0.10.0-5.el10_2 – < *
Red Hat · Red Hat Enterprise Linux 10.0 Extended Update Support
- unaffected 0:0.10.0-3.el10_0.4 – < *
Red Hat · Red Hat Enterprise Linux 8
- unaffected 0:0.4.0-3.el8_10 – < *
Red Hat · Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
- unaffected 0:0.4.0-3.el8_4 – < *
Red Hat · Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On
- unaffected 0:0.4.0-3.el8_4 – < *
Red Hat · Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
- unaffected 0:0.4.0-3.el8_6 – < *
Red Hat · Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On
- unaffected 0:0.4.0-3.el8_6 – < *
Red Hat · Red Hat Enterprise Linux 8.8 Telecommunications Update Service
- unaffected 0:0.4.0-3.el8_8 – < *
Red Hat · Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
- unaffected 0:0.4.0-3.el8_8 – < *
Red Hat · Red Hat Enterprise Linux 9
- unaffected 0:0.6.3-1.el9_8.1 – < *
Red Hat · Red Hat Enterprise Linux 9
- unaffected 0:0.6.3-1.el9_9.1 – < *
Red Hat · Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions
- unaffected 0:0.4.1-7.el9_2.1 – < *
Red Hat · Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions
- unaffected 0:0.4.1-7.el9_4.1 – < *
Red Hat · Red Hat Enterprise Linux 9.6 Extended Update Support
- unaffected 0:0.4.1-8.el9_6.1 – < *
Red Hat · Red Hat Hardened Images
All versions: unaffected
What to do
Workaround: Do not create files on untrusted content with unpatched bwrap. Do not install untrusted Flatpaks. No upstream fix for older setuid builds.
References
References19
- RHSA-2026:85306 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:85308 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:85309 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:85312 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:85313 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:85317 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:85319 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:85322 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:85324 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:85325 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:98521 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-87766 (opens in a new tab)vdb-entryx_refsource_REDHAT
- https://bugs.debian.org/1145655 (opens in a new tab)
- RHBZ#2530542 (opens in a new tab)issue-trackingx_refsource_REDHAT
- https://github.com/containers/bubblewrap/releases/tag/v0.12.0 (opens in a new tab)
- https://github.com/containers/bubblewrap/security/advisories/GHSA-pxhw-h44j-8pfx (opens in a new tab)
- https://www.openwall.com/lists/oss-security/2026/08/27/7 (opens in a new tab)
- http://www.openwall.com/lists/oss-security/2026/09/09/3 (opens in a new tab)
- http://www.openwall.com/lists/oss-security/2026/09/22/23 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-74778 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-87766)Record last updated .