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Fencer Vulns
high 8.8

CVE-2026-87766 json

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

published 2026-09-09 2 mo ago modified 2026-11-02 6 d ago also EUVD-2026-74778

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 11%
public exploits
0
none known

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. This issue is GHSA-pxhw-h44j-8pfx. It is fixed in bubblewrap 0.12.0.

Patch / fix

  • Red Hat Red Hat Enterprise Linux 10 0:0.10.0-5.el10_2
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support 0:0.10.0-3.el10_0.4
  • Red Hat Red Hat Enterprise Linux 8 0:0.4.0-3.el8_10
  • Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support 0:0.4.0-3.el8_4
  • Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On 0:0.4.0-3.el8_4
  • Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support 0:0.4.0-3.el8_6
  • Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On 0:0.4.0-3.el8_6
  • Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service 0:0.4.0-3.el8_8
  • Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions 0:0.4.0-3.el8_8
  • Red Hat Red Hat Enterprise Linux 9 0:0.6.3-1.el9_8.1
  • Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions 0:0.4.1-7.el9_2.1
  • Red Hat Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions 0:0.4.1-7.el9_4.1
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support 0:0.4.1-8.el9_6.1
  • bubblewrap Debian 13 0.12.0-1~deb13u1
  • bubblewrap Debian 14 0.12.0-1

debian advisories DEBIAN-CVE-2026-87766

  • bubblewrap RHEL 10.2 0.10.0-5.el10_2
  • bubblewrap RHEL 9 0.6.3-1.el9_8.1
  • bubblewrap RHEL 8 0.4.0-3.el8_10
  • bubblewrap RHEL 9.6 EUS 0.4.1-8.el9_6.1
  • bubblewrap RHEL 9.2 E4S 0.4.1-7.el9_2.1
  • bubblewrap RHEL 8.6 EUS_LONG_LIFE, RHEL 8.6 AUS 0.4.0-3.el8_6
  • bubblewrap RHEL 8.4 EUS_LONG_LIFE, RHEL 8.4 AUS 0.4.0-3.el8_4
  • bubblewrap RHEL 9.4 E4S 0.4.1-7.el9_4.1

red hat advisories RHSA-2026:85325RHSA-2026:85322RHSA-2026:85324RHSA-2026:85317RHSA-2026:85319RHSA-2026:85312

  • flatpak openSUSE Tumbleweed 1.18.3-1.1

opensuse advisories openSUSE-SU-2026:11873-1

  • bubblewrap AlmaLinux 8 0.4.0-3.el8_10
  • bubblewrap AlmaLinux 10 0.10.0-5.el10_2
  • bubblewrap AlmaLinux 9 0.6.3-1.el9_8.1

almalinux advisories ALSA-2026:85306ALSA-2026:85308ALSA-2026:85309

  • bubblewrap Rocky Linux 10 0.10.0-5.el10_2
  • bubblewrap Rocky Linux 9 0.6.3-1.el9_8.1
  • bubblewrap Rocky Linux 8 0.4.0-3.el8_10

rocky linux advisories RLSA-2026:85308RLSA-2026:85309RLSA-2026:85306

  • bubblewrap Azure Linux 3.0 0.12.0-1

azure linux advisories AZL-100908

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-87766 updated cvss 8.8

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

  • Red Hat Enterprise Linux BaseOS (v. 8) bubblewrap 0.4.0-3.el8_10
    fixed: vendor fix “Do not create files on untrusted content with unpatched bwrap. Do not install untrusted Flatpaks. No upstream fix for older setuid builds.” RHSA-2026:85306
  • Red Hat Enterprise Linux BaseOS (v. 9) bubblewrap 0.6.3-1.el9_8.1
    fixed: vendor fix “Do not create files on untrusted content with unpatched bwrap. Do not install untrusted Flatpaks. No upstream fix for older setuid builds.” RHSA-2026:85309
  • Red Hat Enterprise Linux BaseOS (v. 10) bubblewrap 0.10.0-5.el10_2
    fixed: vendor fix “Do not create files on untrusted content with unpatched bwrap. Do not install untrusted Flatpaks. No upstream fix for older setuid builds.” RHSA-2026:85308
  • Red Hat Enterprise Linux BaseOS AUS (v.8.4) bubblewrap 0.4.0-3.el8_4
    fixed: vendor fix “Do not create files on untrusted content with unpatched bwrap. Do not install untrusted Flatpaks. No upstream fix for older setuid builds.” RHSA-2026:85317
  • Red Hat Enterprise Linux BaseOS AUS (v.8.6) bubblewrap 0.4.0-3.el8_6
    fixed: vendor fix “Do not create files on untrusted content with unpatched bwrap. Do not install untrusted Flatpaks. No upstream fix for older setuid builds.” RHSA-2026:85324
  • Red Hat Enterprise Linux BaseOS E4S (v.8.8) bubblewrap 0.4.0-3.el8_8
    fixed: vendor fix “Do not create files on untrusted content with unpatched bwrap. Do not install untrusted Flatpaks. No upstream fix for older setuid builds.” RHSA-2026:85313
  • Red Hat Enterprise Linux BaseOS E4S (v.9.2) bubblewrap 0.4.1-7.el9_2.1
    fixed: vendor fix “Do not create files on untrusted content with unpatched bwrap. Do not install untrusted Flatpaks. No upstream fix for older setuid builds.” RHSA-2026:85322
  • Red Hat Enterprise Linux BaseOS E4S (v.9.4) bubblewrap 0.4.1-7.el9_4.1
    fixed: vendor fix “Do not create files on untrusted content with unpatched bwrap. Do not install untrusted Flatpaks. No upstream fix for older setuid builds.” RHSA-2026:85319
show 6 more
  • Red Hat Enterprise Linux BaseOS EUS (v. 10.0) bubblewrap 0.10.0-3.el10_0.4
    fixed: vendor fix “Do not create files on untrusted content with unpatched bwrap. Do not install untrusted Flatpaks. No upstream fix for older setuid builds.” RHSA-2026:85312
  • Red Hat Enterprise Linux BaseOS EUS (v.9.6) bubblewrap 0.4.1-8.el9_6.1
    fixed: vendor fix “Do not create files on untrusted content with unpatched bwrap. Do not install untrusted Flatpaks. No upstream fix for older setuid builds.” RHSA-2026:85325
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) bubblewrap 0.4.0-3.el8_4
    fixed: vendor fix “Do not create files on untrusted content with unpatched bwrap. Do not install untrusted Flatpaks. No upstream fix for older setuid builds.” RHSA-2026:85317
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) bubblewrap 0.4.0-3.el8_6
    fixed: vendor fix “Do not create files on untrusted content with unpatched bwrap. Do not install untrusted Flatpaks. No upstream fix for older setuid builds.” RHSA-2026:85324
  • Red Hat Enterprise Linux BaseOS TUS (v.8.8) bubblewrap 0.4.0-3.el8_8
    fixed: vendor fix “Do not create files on untrusted content with unpatched bwrap. Do not install untrusted Flatpaks. No upstream fix for older setuid builds.” RHSA-2026:85313
  • Red Hat Hardened Images bubblewrap
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
1 mo ago

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Affected products

  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
  • Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On
  • Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
  • Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On
  • Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service
  • Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support
  • Red Hat Red Hat Hardened Images

Classification

Weakness
  • CWE-59 Improper Link Resolution Before File Access

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.