Threats / Atlassian / CVE-2021-26086
CVE-2021-26086
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Atlassian Jira Server and Data Center vulnerability
Atlassian Jira Server and Data Center contain a path traversal vulnerability allowing remote attackers to read files in the /WEB-INF/web.xml endpoint, exposing sensitive configuration data.
Verdict
Today item — known-exploited.
A path traversal flaw in Jira Server and Data Center permits unauthenticated remote file access. The high EPSS score and active exploitation indicate immediate risk to exposed instances. Patching is critical.
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
358 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2024-11-12).
Probability (EPSS)
EPSS 0.99999 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Atlassian, Jira Server and Data Center. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-22 Path Traversal — weakness family: Path traversal / file.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft a malicious request using path traversal sequences to bypass directory restrictions and access the /WEB-INF/web.xml file.
Business
Sensitive application configuration, database credentials, and internal system details are exposed to the attacker.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I extract credentials and system information from the exposed configuration files to plan further attacks.
Business
Attackers gain intelligence for lateral movement, privilege escalation, or attacks against downstream systems.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05