EchelonGraph verdictPlan mitigationRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
- •High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 16%CVSS: 9.1Exploit: No code on recordExposed services: Not assessed
No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.
CISA-ADP, in the CVE record, lists atlassian jira_service_management versions 5.3.0 up to but not including 5.3.3 and 5.4.0 up to but not including 5.4.2 as affected. No release containing a fix is confirmed on record.
An authentication vulnerability was discovered in Jira Service Management Server and Data Center which allows an attacker to impersonate another user and gain access to a Jira Service Management instance under certain circumstances_._ With write access to a User Directory and outgoing email enabled on a Jira Service Management instance, an attacker could gain access to signup tokens sent to users with accounts that have never been logged into. Access to these tokens can be obtained in two cases:
* If the attacker is included on Jira issues or requests with these users, or
* If the attacker is forwarded or otherwise gains access to emails containing a “View Request” link from these users.
Bot accounts are particularly susceptible to this scenario. On instances with single sign-on, external customer accounts can be affected in projects where anyone can create their own account.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (9.1): severity, escalated by confirmed exploitation. This CVE's 9.1 is its impact severity (EG Severity), not escalated.
- EG Severity
- 9.1 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 16% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-23). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 3 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).
No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)3 days if the affected system is publicly exposed; 60 days if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it