How severe is CVE-2026-42354?

CVE-2026-42354 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2026-42354 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-42354?

CVE-2026-42354 affects Sentry. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-42354?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-42354 have an EU (EUVD) identifier?

Yes. CVE-2026-42354 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-28860.

When was CVE-2026-42354 published?

CVE-2026-42354 was published on 2026-05-08 and last updated on 2026-06-17.

CVE-2026-42354

CVE-2026-42354 is a critical-severity vulnerability in Sentry with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-290.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
EPSS exploit prediction: 1% (46th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-28860
Weakness: CWE-290
Affected product: Sentry
Published: 2026-05-08
Last modified: 2026-06-17

Description

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 been patched in version 26.4.1.

Frequently asked questions

What is CVE-2026-42354?: 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 been patched in version 26.4.1.
How severe is CVE-2026-42354?: CVE-2026-42354 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-42354 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-42354?: CVE-2026-42354 affects Sentry. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-42354?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-42354 have an EU (EUVD) identifier?: Yes. CVE-2026-42354 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-28860.
When was CVE-2026-42354 published?: CVE-2026-42354 was published on 2026-05-08 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:sentry:sentry:*:*:*:*:*:*:*:*

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