CVE-2026-48090: Envoy is an open source edge and service proxy designed for cloud-native applications

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MEDIUM 5.9REMOTEUPGRADE

CVE-2026-48090 is a medium-severity flaw (CVSS 5.9) affecting envoy. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 be

Why this priority

Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.9 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 53%)
CISA exploited list	No
Weakness	CWE-416
Published	2026-06-26
Last modified	2026-10-25

Publisher (CNA): GitHub, Inc. · Vendor: envoyproxy

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-26 19:16 UTCPublished CVE record published
2026-10-25 17:10 UTCUpdated Record last modified

envoyproxy envoy UPGRADE

Affected: >= 1.37.0 and < 1.37.5 · >= 1.38.0 and < 1.38.3

Fixed in: 1.37.5, 1.38.3

Safe to downgrade to: a release before 1.37.0

1. Check installed version

apt-cache policy envoy || rpm -q envoy || envoy --version

2. UPGRADE to 1.37.5 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade envoy

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade envoy

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 1.37.0 (Debian / Ubuntu)

apt-cache madison envoy sudo apt install envoy=<VERSION_BEFORE_1.37.0> sudo apt-mark hold envoy

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list envoy sudo dnf downgrade envoy-<VERSION_BEFORE_1.37.0> sudo dnf versionlock add envoy

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-48090?

envoy: upgrade to 1.37.5, 1.38.3. Exact commands for each OS are on this page.

Is CVE-2026-48090 being exploited?

CVE-2026-48090 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-48090 affect?

CVE-2026-48090 affects envoy. Severity is medium (CVSS 5.9). 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 downstr

How urgent is CVE-2026-48090?

Priority 42/100. Public exploit reference; Remotely exploitable, no login, no user action

Software pages

Envoy vulnerabilities

Related CVEs

CVE-2026-47220 HIGH 7.5 UPGRADE Envoy is an open source edge and service proxy designed for cloud-native applications
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CVE-2026-48044 HIGH 7.5 UPGRADE Envoy is an open source edge and service proxy designed for cloud-native applications
CVE-2026-48743 HIGH 7.5 UPGRADE Envoy is an open source edge and service proxy designed for cloud-native applications
CVE-2026-47221 MEDIUM 5.9 UPGRADE Envoy is an open source edge and service proxy designed for cloud-native applications

References

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