Local Blobstore may allow arbitrary reads/deletes

published 2026-05-27 5 mo ago modified 2026-10-26 13 d ago also EUVD-2026-32098

cvss: 5.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.1%; EPSS 0.1% chance of exploitation in 30 days, percentile 0%
public exploits: 0; none known

When the director sends a long-running request (e.g. compile_package), the agent's reply JSON is consumed by AgentClient. inject_compile_log (line 332-339) reads response['value']['result']['compile_log_id'] and format_exception (line 318-325) reads exception['blobstore_id']; both pass the agent-supplied string unmodified to download_and_delete_blob(blob_id) (line 344-349), which calls @resource_manager.get_resource(blob_id) and, in an ensure block, @resource_manager.delete_resource(blob_id). Api::ResourceManager forwards the id straight to blobstore.get(id) / blobstore.delete(id). When the director is configured with the local blobstore provider, Blobstore::LocalClient#object_file_path(oid) is File.join(@blobstore_path, oid) (local_client.rb:54-56) with no normalisation, so oid = "../../jobs/director/config/director.yml" resolves outside the blobstore root.

Affected versions: BOSH Director: All versions prior to v282.1.12

Patch / fix

fixed in 1

Cloud Foundry Foundation BOSH Director 282.1.12

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 5 mo ago (2026-05-27)

Exploit prediction

0.10% chance of exploitation in the next 30 days, higher than 0% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	4.3	CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:P/VC:N/VI:H/VA:L/SC:N/SI:N/SA:L
CNA	3.1	5.8	CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:C/C:N/I:H/A:L
CNA	4.0	4.3	CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:P/VC:N/VI:H/VA:L/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

Cloud Foundry Foundation BOSH Director

Classification

Weakness

CWE-22 Improper Limitation of a Pathname to a Restricted Directory

References

cloudfoundry.org /blog/cve-2026-41009-local-blobstore-may-allow-arbitrary-reads-deletes/
mitigation, vendor-advisory

Sources

CVE List CVE-2026-41009
NVD CVE-2026-41009

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.

Summary