# CVE-2026-48090: Envoy HTTP: OAuth2 filter late async token completion after stream teardown (UAF / crash risk)

> A use-after-free in the Envoy OAuth2 filter allows remote attackers to cause worker crashes and denial of service via late async token completions.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 26 Jun 2026
- **Updated:** 8 Jul 2026
- **Also known as:** BIT-envoy-2026-48090, GHSA-3cj2-c63f-q26f

## What is CVE-2026-48090?

CVE-2026-48090 is a medium-severity use after free vulnerability in Envoyproxy Envoy, published on 26 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.37.0 until 1.37.5 and 1.38.3, the HTTP OAuth2 filter (envoy.filters.http.oauth2) can leave an in-flight async token exchange attached to a downstream stream that has already been torn down. A late AsyncClient completion can still invoke OAuth2Filter methods that use StreamDecoderFilterCallbacks after that object’s lifetime has ended, causing undefined behavior, worker crashes (availability loss), and use-after-free / invalid-vptr failures under AddressSanitizer. This is a memory-safety / lifetime issue in the data plane, not a trivial config bug. Remote code execution is not claimed here; the primary demonstrated impact is DoS via crash and UB; any further impact would be deployment- and allocator-dependent.  This vulnerability is fixed in 1.37.5 and 1.38.3.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-48090?

1 open source package ship an affected version, including envoy. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `envoy` | Bitnami | From 1.37.0 | 1.37.5, 1.38.3 |

Products: Envoyproxy Envoy.

## How do I fix CVE-2026-48090?

Upgrade envoy to a fixed version for your release line: 1.37.5 or 1.38.3.

## Is CVE-2026-48090 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-48090 exists.

## Other vulnerabilities in Envoyproxy Envoy

- [CVE-2022-29226](https://insights.sbomify.com/CVE-2022-29226/): Trivial authentication bypass in Envoy (critical 10.0)
- [CVE-2019-18801](https://insights.sbomify.com/CVE-2019-18801/): Memory corruption in n/a (critical 9.8)
- [CVE-2019-18802](https://insights.sbomify.com/CVE-2019-18802/): Security feature bypass in n/a (critical 9.8)
- [CVE-2020-35470](https://insights.sbomify.com/CVE-2020-35470/): Information disclosure in n/a (high 8.8)
- [CVE-2024-23324](https://insights.sbomify.com/CVE-2024-23324/): Envoy ext auth can be bypassed when Proxy protocol filter sets invalid UTF-8 metadata (high 8.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-48090 and fix it if it is affected.

What it is: CVE-2026-48090 is a medium-severity use after free vulnerability in Envoyproxy Envoy, published on 26 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-48090 exists.

Affected packages and fixed versions:
- envoy (Bitnami): affected from 1.37.0; fixed in 1.37.5, 1.38.3

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-48090/ (Markdown: https://insights.sbomify.com/CVE-2026-48090/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-48090
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-48090
- OSV: https://osv.dev/vulnerability/CVE-2026-48090

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-48090/
Summaries are generated and may contain mistakes; the official description above is the record.