What is CVE-2021-26309?

CVE-2021-26309 is a low-severity vulnerability in Jetbrains Teamcity, classified under Exposure of Resource to Wrong Sphere. CVSS score: 3.3/10. Published 2021-05-11.

How severe is CVE-2021-26309?

Low severity. CVSS v3 base score is 3.3 out of 10.

Vulnerability in Jetbrains Teamcity

CVE-2021-26309

Information disclosure in the TeamCity plugin for IntelliJ before 2020.2.2.85899 was possible because a local temporary file had Insecure Permissions.

Published 2021-05-11 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 3.3 (Low). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.002 (12.8th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 12.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Jetbrains Teamcity

Weakness classification (CWE)

CWE-668 — Exposure of Resource to Wrong Sphere

References

blog.jetbrains.com (Vendor Advisory)
blog.jetbrains.com/blog/2021/05/07/jetbrains-security-bulletin-q1-2021/ (Vendor Advisory)

Frequently asked questions

What is CVE-2021-26309?: CVE-2021-26309 is a low-severity vulnerability in Jetbrains Teamcity, classified under Exposure of Resource to Wrong Sphere. CVSS score: 3.3/10. Published 2021-05-11.
How severe is CVE-2021-26309?: Low severity. CVSS v3 base score is 3.3 out of 10.