CVE-2026-31838Network attack vector

Cross-namespace proxy data disclosure via missing caller context

Published Mar 10, 2026 · Updated Mar 10, 2026

Information disclosure in Istio before 1.27.8, 1.28.0 through 1.28.4, and 1.29.0 allows remote authenticated users to read proxy data. The XDS DebugGen handler on ports 15012 and 15014 forwards internal debug requests without placing the verified workload namespace in CallerNamespaceKey, so the downstream namespace check is skipped. ENABLE_DEBUG_ENDPOINT_AUTH must be enabled, and any authenticated non-system workload can request config_dump data exposing other namespaces' routing, endpoints, and topology.

CVSS severity6.9
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Istio before 1.27.8, 1.28.0 through 1.28.4, and 1.29.0 allows remote authenticated users to read proxy data. The XDS DebugGen handler on ports 15012 and 15014 forwards internal debug requests without placing the verified workload namespace in CallerNamespaceKey, so the downstream namespace check is skipped. ENABLE_DEBUG_ENDPOINT_AUTH must be enabled, and any authenticated non-system workload can request config_dump data exposing other namespaces' routing, endpoints, and topology.

The record

CVE
CVE-2026-31838
Published
Mar 10, 2026
Updated
Mar 10, 2026
Vendor
Istio
Product
Istio
Classifications
CWE-863, T1613
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.27.8
  2. Affected versionversion=>= 1.28.0-alpha.0, < 1.28.5
  3. Affected versionversion=>= 1.29.0-alpha.0, < 1.29.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Istio · Istioversion=< 1.27.8; version=>= 1.28.0-alpha.0, < 1.28.5; version=>= 1.29.0-alpha.0, < 1.29.1

Published CVSS scores

6.9GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N
5.3NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-863Incorrect Authorization
T1613Container and Resource Discovery

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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