- Published
- Source
- CSO Online UK
- Filed under
- UK industry, Malware & exploits
- Vulnerabilities
- 1 CVE Exploited
A newly-disclosed critical flaw in Atlassian’s data center software has a remarkably wide reach, affecting eight core products across the company’s enterprise portfolio. CVE-2026-21589, rated 9.3 (critical) in severity, is an arbitrary file access vulnerability that could allow an attacker with no login access to read files in web app root directories that they should…
If you run the affected product
- Find every instance – especially the ones reachable from the internet.
- Apply the vendor's patch or mitigation now: exploited flaws are fixed in days, not at the next patch cycle.
- Then check for signs it was used before you patched: web shells, new accounts, unusual outbound traffic.
More helpCISA's Known Exploited Vulnerabilities catalogue (opens in a new tab)
The vulnerabilities in this story
CVE-2026-21589 in the NVD (opens in a new tab)
- CVSS9.3Critical
- EPSS13%chance of exploitation in 30 days
- CISA KEVExploitedon the list since 15 Oct
Exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog (CC0). Exploit prediction: EPSS by FIRST. This product uses the NVD API but is not endorsed or certified by the NVD.
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