NVD / CVE Program· CNA GitHub_M

CVE-2025-54588: Envoy: Race condition in Dynamic Forward Proxy leads to use-after-free and segmentation faults

Noroxi assessment

Priority: Monitor (action score 30/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.47% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: github.com/envoyproxy/envoy (Go) 1.34.5, 1.35.1.

Low priority for now. Upgrade to github.com/envoyproxy/envoy (Go) 1.34.5, 1.35.1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Envoy is an open source L7 proxy and communication bus designed for large modern service oriented architectures. Versions 1.34.0 through 1.34.4 and 1.35.0 contain a use-after-free (UAF) vulnerability in the DNS cache, causing abnormal process termination. The vulnerability is in Envoy's Dynamic Forward Proxy implementation, occurring when a completion callback for a DNS resolution triggers new DNS resolutions or removes existing pending resolutions. This condition may occur when the following conditions are met: dynamic Forwarding Filter is enabled, the `envoy.reloadable_features.dfp_cluster_resolves_hosts` runtime flag is enabled, and the Host header is modified between the Dynamic Forwarding Filter and Router filters. This issue is resolved in versions 1.34.5 and 1.35.1. To work around this issue, set the envoy.reloadable_features.dfp_cluster_resolves_hosts runtime flag to false.

HighCVSS 7.5 · v3.1—No exploit Fix available

GHSA-g9vw-6pvx-7gmw

Published: Sep 2, 2025
Updated: Jun 17, 2026
EPSS: 0.4% · 41th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 30 / 40 · 7.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.4%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · GitHub_M: 7.5; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
envoyproxy	envoy	cpe:2.3:a:envoyproxy:envoy

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

envoyproxy envoy1.34.0 and later · before 1.34.5
envoyproxy envoy1.35.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

envoyproxy envoy
- >= 1.34.0, < 1.34.5, >= 1.35.0, < 1.35.1affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Go	github.com/envoyproxy/envoy	from 1.34.0 · before 1.34.5	1.34.5
Go	github.com/envoyproxy/envoy	from 1.35.0 · before 1.35.1	1.35.1

Same product

envoyproxy: all records

Other highest-scoring records for the same primary product.

CVE-2024-30255HTTP/2: CPU exhaustion due to CONTINUATION frame flood
56Plan
CVE-2024-27919HTTP/2: memory exhaustion due to CONTINUATION frame flood
56Plan
CVE-2021-29492Bypass of path matching rules using escaped slash characters
52Plan

Published before and after this one in the same product

← EarlierCVE-2025-30157Mar 21, 2025 · Envoy crashes when HTTP ext_proc processes local replies
30Monitor
← EarlierCVE-2025-46821May 7, 2025 · Envoy vulnerable to bypass of RBAC uri_template permission
21Monitor
Later →CVE-2025-55162Sep 3, 2025 · Envoy: oAuth2 Filter Signout route will not clear cookies because of missing "secure;" flag
35Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Go:github.com/envoyproxy/envoy	1.34.5	Package registry (OSV)
Go:github.com/envoyproxy/envoy	1.35.1	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2024-39305428 days apartEnvoy Proxy use after free when route hash policy is configured with cookie attributes
36Monitor
CVE-2025-6250444 days apartEnvoy Lua filter use-after-free when oversized rewritten response body causes crash
30Monitor
CVE-2026-26330189 days apartEnvoy global rate limit may crash when the response phase limit is enabled and the response phase request is failed directly
30Monitor
CVE-2026-73512384 days apartEnvoy: use-after-free in QUIC on internal redirects
30Monitor
CVE-2024-32974455 days apartEnvoy affected by a crash in EnvoyQuicServerStream::OnInitialHeadersComplete()
30Monitor
CVE-2026-47207297 days apartEnvoy crashes if multiple unexpected ext_proc responses are packed into one gRPC message
26Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: none
Integrity: none
Availability: high · the service can be disrupted

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

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

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

nvd-secondary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

Fix✗ → ✓Sep 28, 2026, 10:48 PM UTC

For records you follow, these changes also arrive as notifications. →

References

github.com/envoyproxy/envoy/releases/tag/v1.34.5

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records