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Wasm cache ServeHTTP reads mappingPath2Cache without lock

Moderate
zirain published GHSA-8fv2-88gg-hm7q Jun 5, 2026

Package

Gateway (Envoy)

Affected versions

< 1.7.4, < 1.8.1

Patched versions

1.7.4, 1.8.1

Description

Vulnerability report without repro case. Repro case may be added later after harness is complete.

Preconditions (4):

  • Pod-network reachability to :18002 (no auth)
  • Tenant can create EnvoyExtensionPolicy (baseline)
  • Attacker pod floods GET while churning EnvoyExtensionPolicy with distinct Wasm URLs
  • Read at :153 must overlap a write at :201/:209 (probabilistic, attacker controls both rates)

Description:

httpserver.go:153 reads s.mappingPath2Cache with no lock while httpserver.go:201/209 write it under s.Lock(); the struct uses a plain map. Writer is tenant-reachable via EnvoyExtensionPolicy translation, reader is pod-network-reachable on :18002 with per-request goroutines. Go's concurrent map read+write detection calls runtime.throw, which net/http's per-conn recover cannot catch, so the controller process exits — cross-tenant control-plane DoS. Capped at MEDIUM: DoS-only, k8s restarts pod, timing-dependent trigger.

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

CVE ID

CVE-2026-53715

Weaknesses

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently. Learn more on MITRE.

Credits