9.8

CVE-2026-42354: Sentry: Improper authentication on SAML SSO process allows user identity linking

Analyzed
AliasesGHSA-rcmw-7mc7-3rj7PYSEC-2026-534
Published 08-05-2026Last modified 11-05-2026

Vulnerability summary

CVE-2026-42354 is a critical (CVSS 9.8) Authentication Bypass by Spoofing vulnerability in getsentry sentry. EPSS estimates a 0.62% chance of exploitation in the next 30 days, higher than 49.9% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 9.1 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
9.8/10
010
Critical · v3.1 (NVD)
EPSS score
0.62%
0%100%
Low · -0.11 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 08-05-2026
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.62%

Chance of exploitation in the next 30 days

Percentile

50%

Versus all other CVEs

30-day change

Decrease -0.11 pp

From 0.73% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Getsentry1 product
PyPI1 product
  • sentry≥ 21.12.0, < 26.4.1
Sentry1 product

3 vendors · 3 products

References

8 links