CVE-2026-42354: Sentry is an error tracking and performance monitoring tool

This month

CRITICAL 9.1REMOTEUPGRADE

CVE-2026-42354 is a critical-severity flaw (CVSS 9.1) affecting sentry. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Sentry is an error tracking and performance monitoring tool. From version 21.12.0 to before version 26.4.1, a critical vulnerability was discovered in the SAML SSO implementation of Sentry. The vulnerability allows an attacker to take over any user account by using a malicious SAML Identity Provider and another organization on the same Sentry instance. The victim email address must be known in order to exploit this vulnerability. This issue has b

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.1 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 50%)
CISA exploited list	No
Weakness	CWE-290
Published	2026-05-08
Last modified	2026-07-24

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

Last updated 2026-07-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-08 23:16 UTCPublished CVE record published
2026-07-24 21:10 UTCUpdated Record last modified

sentry sentry UPGRADE

Affected: >= 21.12.0 and < 26.4.1

Fixed in: 26.4.1

Safe to downgrade to: a release before 21.12.0

1. Check installed version

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

2. UPGRADE to 26.4.1 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade sentry

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 21.12.0 (Debian / Ubuntu)

apt-cache madison sentry sudo apt install sentry=<VERSION_BEFORE_21.12.0> sudo apt-mark hold sentry

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

dnf --showduplicates list sentry sudo dnf downgrade sentry-<VERSION_BEFORE_21.12.0> sudo dnf versionlock add sentry

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-2026-42354?

sentry: upgrade to 26.4.1. Exact commands for each OS are on this page.

Is CVE-2026-42354 being exploited?

CVE-2026-42354 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-2026-42354 affect?

CVE-2026-42354 affects sentry. Severity is critical (CVSS 9.1). Sentry is an error tracking and performance monitoring tool. From version 21.12.0 to before version 26.4.1, a critical vulnerability was discovered in the SAML SSO implementation of Sentry. The vulnerability allows an attacker to take over

How urgent is CVE-2026-42354?

Priority 49/100. Critical severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-52794 HIGH 7.5 UPGRADE Sentry is an error tracking and performance monitoring tool

References

← Back to latest CVEs