CVE-2026-100267: In JetBrains YouTrack before 2026.2.19197 reDoS attack was possible via mailbox regex mail-rule filters

Q: How do I fix CVE-2026-100267?

youtrack: upgrade to 2026.2.19197. Exact commands for each OS are on this page.

Q: Is CVE-2026-100267 being exploited?

CVE-2026-100267 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-100267 affect?

CVE-2026-100267 affects youtrack. Severity is medium (CVSS 5.9). In JetBrains YouTrack before 2026.2.19197 reDoS attack was possible via mailbox regex mail-rule filters

Q: How urgent is CVE-2026-100267?

Priority 31/100. Remotely exploitable, no login, no user action

Routine

MEDIUM 5.9REMOTEUPGRADE

CVE-2026-100267 is a medium-severity flaw (CVSS 5.9) affecting youtrack. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In JetBrains YouTrack before 2026.2.19197 reDoS attack was possible via mailbox regex mail-rule filters

Why this priority

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	0.3% (top 79%)
CISA exploited list	No
Weakness	CWE-1333
Published	2026-09-30
Last modified	2026-10-01

Publisher (CNA): JetBrains s.r.o. · Vendor: jetbrains

Last updated 2026-10-01 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-09-30 16:16 UTCPublished CVE record published
2026-10-01 15:25 UTCUpdated Record last modified

jetbrains youtrack UPGRADE

Affected: < 2026.2.19197

Fixed in: 2026.2.19197

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 2026.2.19197 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade youtrack

Note

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

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-2026-100267?

youtrack: upgrade to 2026.2.19197. Exact commands for each OS are on this page.

Is CVE-2026-100267 being exploited?

CVE-2026-100267 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-2026-100267 affect?

CVE-2026-100267 affects youtrack. Severity is medium (CVSS 5.9). In JetBrains YouTrack before 2026.2.19197 reDoS attack was possible via mailbox regex mail-rule filters

How urgent is CVE-2026-100267?

Priority 31/100. Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-57923 MEDIUM 5.3 UPGRADE In JetBrains YouTrack before 2026.2.16593 improper authorisation in the app configurations endpoint allowed mo
CVE-2026-57921 MEDIUM 4.3 UPGRADE In JetBrains YouTrack before 2026.2.16593 improper access control allowed reading users' private data via the
CVE-2026-57924 MEDIUM 4.3 UPGRADE In JetBrains YouTrack before 2026.2.16593 default role configuration exposed excessive user profile details
CVE-2026-57925 MEDIUM 4.3 UPGRADE In JetBrains YouTrack before 2026.2.16593 improper access control allowed reading saved queries and tags
CVE-2026-57926 LOW 2.6 UPGRADE In JetBrains YouTrack before 2026.2.16593 the websandbox bridge was vulnerable to a prototype pollution attack

References

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