What is the CVSS score of CVE-2026-53717?

CVE-2026-53717 has a CVSS 3.1 base score of 6.5 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2026-53717?

Yes, a patch is available for CVE-2026-53717. Update the affected software to the latest version immediately.

Envoy Gateway CVE-2026-53717

MEDIUM

Memory Allocation with Excessive Size Value (CWE-789)

2026-07-16 https://github.com/envoyproxy/gateway

GHSA-h7pq-86h8-rp5x

Docker Denial Of Service

6.5

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

6.5 MEDIUM

AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

vuln.today AI

6.5 MEDIUM

Network-reachable via Kubernetes API with low privilege (tenant RBAC); no confidentiality or integrity impact; full availability loss via unrecoverable OOM.

3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L

Primary rating from GitHub Advisory.

CVSS VectorGitHub Advisory

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

Source Code Evidence Fetched

Jul 16, 2026 - 19:51 vuln.today

Analysis Generated

Jul 16, 2026 - 19:51 vuln.today

DescriptionGitHub Advisory

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

Preconditions (4):

Tenant can create EnvoyExtensionPolicy (baseline)
Controller has egress to attacker-controlled OCI registry
No registry allowlist (none exists in code)
Layer presents Docker/OCI media type

Description

At imagefetcher.go:287, make([]byte, h.Size) uses the attacker-controlled tar-header size; the LimitReader at :278 bounds bytes read from the stream but not the header-declared size returned by tr.Next() (a 512-byte header can claim a multi-TB entry via PAX/GNU encoding). Reached from untrusted tenant input via EnvoyExtensionPolicy spec.wasm[].code.image.url (envoyextensionpolicy.go:1157 → cache.go:262/299 → imagefetcher.go:218 → :287), and the allocation happens for every tar entry regardless of filename. The resulting Go runtime OOM throw is unrecoverable and, because the CRD persists, crash-loops the shared controller - single-request, non-volumetric, cluster-wide DoS.

AnalysisAI

Uncontrolled memory allocation in Envoy Gateway's OCI image fetcher allows a low-privileged tenant to crash-loop the shared controller cluster-wide. Versions before 1.7.4 and in the 1.8.x pre-release range before 1.8.1 are affected. …

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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata

Recon

Obtain EnvoyExtensionPolicy RBAC create rights

Delivery

Stand up attacker-controlled OCI registry

Exploit

Craft tar layer with PAX/GNU oversized header entry

Install

Submit malicious EnvoyExtensionPolicy referencing registry URL

Controller fetches and processes OCI image

Execute

make([]byte, multi-TB) triggers Go runtime OOM throw

Impact

Controller crash-loops, cluster-wide DoS persists via CRD

Recon

Obtain EnvoyExtensionPolicy RBAC create rights

Delivery

Stand up attacker-controlled OCI registry

Exploit

Craft tar layer with PAX/GNU oversized header entry

Install

Submit malicious EnvoyExtensionPolicy referencing registry URL

Controller fetches and processes OCI image

Execute

make([]byte, multi-TB) triggers Go runtime OOM throw

Impact

Controller crash-loops, cluster-wide DoS persists via CRD

Vulnerability AssessmentAI

Exploitation	Exploitation requires all four of the following conditions: (1) the attacker holds Kubernetes RBAC permission to create or modify EnvoyExtensionPolicy resources in at least one namespace - this is a tenant-level privilege that should be restricted to trusted operators; (2) the Envoy Gateway controller pod has outbound network egress to the attacker-controlled OCI registry - no registry allowlist is implemented in the codebase to prevent this; (3) the controller is running a vulnerable version (< 1.7.4 or >= 1.8.0-rc.0 and < 1.8.1); (4) the malicious OCI layer presents a Docker or OCI-compatible media type to pass content-type validation. … Additional conditions and limiting factors are described in the full assessment.
Risk Assessment	The CVSS 6.5 (AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H) vector is consistent with the described attack. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario	A tenant with EnvoyExtensionPolicy RBAC create rights submits a policy with a Wasm image URL pointing to an attacker-operated OCI registry. The registry responds with a valid OCI manifest pointing to a tar layer containing a single entry whose PAX-extended header claims a 2 TB size while the actual stream contains only a few bytes. …
Remediation	Upgrade Envoy Gateway to version 1.8.1 (for deployments on the 1.8.x line) or 1.7.4 (for deployments on the 1.7.x line), per the vendor advisory at https://github.com/envoyproxy/gateway/security/advisories/GHSA-h7pq-86h8-rp5x. … Detailed patch versions, workarounds, and compensating controls in full report.