VulnSocial

CVE-2026-31838Patch(istio / istio)

LOWCVSS 5.3 · MEDIUM

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Patch istio istio systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD description

Istio is an open platform to connect, manage, and secure microservices. Prior to 1.29.1, 1.28.5, and 1.27.8, a vulnerability in Envoy RBAC header matching could allow authorization policy bypass when policies rely on HTTP headers that may contain multiple values. An attacker could craft requests with multiple header values in a way that causes Envoy to evaluate the header differently than intended, potentially bypassing authorization checks. This may allow unauthorized requests to reach protected services when policies depend on such header-based matching conditions. This vulnerability is fixed in 1.29.1, 1.28.5, and 1.27.8.

istio CVEsBack to dashboard
0.5/ 10 priority

Sources & remediation

Vendor / third-party advisories
Other references
Weakness type (CWE)
CWE-863

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

STABLE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • istio

Threat summary

  • Patch or workaround signal is available
  • 2 mentions across 2 observed days
  • Momentum state: stable

What's happening

  • Patch or workaround mentioned in 1 signal
  • Technical details provided in 1 signal
  • General: 1 classified signal
  • Peaked 1d ago at 1 mentions (2026-03-10); latest day: 1
  • 2 total mentions across 2 days

Affected systems

Vendors
istio
Products
istio

Deep dive

Activity timeline2 mentions / 2d
00111Mentions · 2026-03-10: 1Mentions · 2026-03-11: 1Patch / Workaround · 2026-03-10: 1Technical Details · 2026-03-10: 103-1003-11
Signal classification2 categories
Patch
150.0%
General
150.0%
Referenced assets3 URLs
Classification over time
DateTotalLabels
2026-03-101
Patch1
2026-03-111
General1
Full discourse2 posts
  • Vulmon Vulnerability Feed@VulmonFeeds
    General

    CVE-2026-31838 Istio Envoy RBAC Header Matching Vulnerability Enables Au... https://vulmon.com/vulnerabilitydetails?qid=CVE-2026-31838 Don't wait vulnerability scanning results: https://alerts.vulmon.com/?utm_source=twitter&utm_medium=social&utm_campaign=2102281&utm_content=2

    Post summary

    The tweet briefly announces CVE-2026-31838 and directs to external links for details, offering no further technical or exploit information.

    0001034
    4.0K followersView on X
  • CVE@CVEnew
    Patch

    CVE-2026-31838 Istio is an open platform to connect, manage, and secure microservices. Prior to 1.29.1, 1.28.5, and 1.27.8, a vulnerability in Envoy RBAC header matching could allow… https://www.cve.org/CVERecord?id=CVE-2026-31838

    Post summary

    The post indicates that Istio versions prior to 1.29.1, 1.28.5, and 1.27.8 contain an Envoy RBAC header matching vulnerability, with upgrading to these versions serving as the recommended fix.

    0000086
    56.7K followersView on X
CPE platform detail1 entries

1 of 1 entries

PartVendorProductVersionTarget SWTarget HW
Appistioistio---

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