CVE-2026-87766

HIGHPre-NVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.1%, top 96% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 3 sources updated this week
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.8Exploit: None knownExposed: 0

A fix is available — apply it.

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 v3
8.8
EG Score
8.8(medium)
EG Risk
40(Track)
EG Risk 40/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity88% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
4%
KEV
Not listed

Published

September 9, 2026

Last Modified

September 9, 2026

Advisory Details (6)

Auto-updated Sep 9, 2026
Patch available. Sources: redhat, github_release, github.
generic

oss-security - bubblewrap 0.12.0 fixes writes outside sandbox

https://www.openwall.com/lists/oss-security/2026/08/27/7
github Patch Available

Sandbox escape: symlink traversal via /oldroot allows writing files outside sandbox during setup · Advisory · containers/bubblewrap · GitHub

https://github.com/containers/bubblewrap/security/advisories/GHSA-pxhw-h44j-8pfx
github_release Patch Available

Release 0.12.0

Patch available: containers/bubblewrap v0.12.0

https://github.com/containers/bubblewrap/releases/tag/v0.12.0
redhat

2530542 – (CVE-2026-87766) CVE-2026-87766 bubblewrap: bubblewrap: symlink traversal via /oldroot allows writing files outside sandbox during setup

https://bugzilla.redhat.com/show_bug.cgi?id=2530542
generic Patch Available

#1145655 - bubblewrap: GHSA-pxhw-h44j-8pfx: sandbox escape via symlink traversal during setup - Debian Bug report logs

https://bugs.debian.org/1145655
redhat Patch Available

CVE-2026-87766 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a

https://access.redhat.com/security/cve/CVE-2026-87766

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntububblewrap (0.6.1-1ubuntu0.2) @ jammy2026-09-18ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

All Vendor Advisories

(2)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 19× in last 7d / 33× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-18 22:02 UTCEG score recompute
  2. 2026-09-18 22:02 UTCVendor advisory
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-18 11:02 UTCVendor advisory
  5. 2026-09-18 00:01 UTCEG score recompute
  6. 2026-09-18 00:01 UTCVendor advisory
  7. 2026-09-17 19:32 UTCEPSS rescore
  8. 2026-09-17 13:00 UTCVendor advisory
  9. 2026-09-17 01:42 UTCVendor advisory
  10. 2026-09-16 14:42 UTCEG score recompute
  11. 2026-09-16 14:42 UTCVendor advisory
  12. 2026-09-16 14:09 UTCEPSS rescore
  13. 2026-09-16 05:15 UTCEPSS rescore
  14. 2026-09-16 03:41 UTCVendor advisory
  15. 2026-09-15 16:40 UTCVendor advisory
  16. 2026-09-15 05:39 UTCEG score recompute
  17. 2026-09-15 03:12 UTCEPSS rescore
  18. 2026-09-13 20:37 UTCEG score recompute
  19. 2026-09-12 22:36 UTCEG score recompute
  20. 2026-09-12 00:34 UTCEG score recompute
  21. 2026-09-11 14:53 UTCEPSS rescore
  22. 2026-09-11 14:53 UTCEPSS rescore
  23. 2026-09-11 13:33 UTCEG score recompute
  24. 2026-09-10 15:31 UTCEG score recompute
  25. 2026-09-09 17:29 UTCEG score recompute
Show 8 more
  1. 2026-09-09 16:38 UTCEG score recompute
  2. 2026-09-09 15:29 UTCEG score recompute
  3. 2026-09-09 14:20 UTCEG score recompute
  4. 2026-09-09 10:25 UTCEG score recompute
  5. 2026-09-09 10:15 UTCEG score recompute
  6. 2026-09-09 09:18 UTCEG score recompute
  7. 2026-09-09 08:46 UTCEG score recompute
  8. 2026-09-09 08:45 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-87766?
CVE-2026-87766 is a high vulnerability published on September 9, 2026. 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…
When was CVE-2026-87766 disclosed?
CVE-2026-87766 was first published in the National Vulnerability Database on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-87766 actively exploited?
CVE-2026-87766 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 96.3% of all scored CVEs.
What is the CVSS score of CVE-2026-87766?
CVE-2026-87766 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2026-87766?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-87766, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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