Unauthorized access to fields protected by Field-Level Security (FLS) when those fields are members of an object

published 2025-10-29 last yr. modified 2026-10-08 last mo. also EUVD-2025-36687

cvss: 6.0; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 20%
public exploits: 0; none known

In Search Guard FLX versions 3.1.1 and earlier, Field-Level Security (FLS) rules are improperly enforced on object-valued fields.

When an FLS exclusion rule (e.g., ~field) is applied to a field which contains an object as its value, the object is correctly removed from the _source returned by search operations. However, the object members (i.e., child attributes) remain accessible to search queries. This exposure allows adversaries to infer or reconstruct the original contents of the excluded object.

Workaround - If you cannot upgrade immediately and FLS exclusion rules are used for object valued attributes (like ~object), add an additional exclusion rule for the members of the object (like ~object.*).

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CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: last yr. (2025-10-29)

Exploit prediction

0.27% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by	version	score	vector
CNA	4.0	6.0	CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
CNA	4.0	6.0	CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/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

floragunn Search Guard FLX

Classification

Weakness

CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
CWE-732 Incorrect Permission Assignment for Critical Resource

References

Sources

CVE List CVE-2025-12147
NVD CVE-2025-12147

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