CyberSecBulletin
CVE-2026-22186NVD status: Modified

Bio-Formats: Improper Restriction of XML External Entity Reference

Published Updated By the CyberSecBulletin desk

CVE-2026-22186 is a high-severity improper restriction of XML external entity reference vulnerability in Bio-Formats from Open Microscopy Environment, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected Bio-Formats versions: 8.3.0 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.17% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Bio-Formats you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
Open Microscopy EnvironmentBio-Formats8.3.0 and earlierNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
RequiredA user must take an action such as opening a file or link.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 4.04.6MediumCNA (vulncheck.com)
CVSS 3.17.1HighNVD

Official description

Bio-Formats versions up to and including 8.3.0 contain an XML External Entity (XXE) vulnerability in the Leica Microsystems metadata parsing component (e.g., XLEF). The parser uses an insecurely configured DocumentBuilderFactory when processing Leica XML-based metadata files, allowing external entity expansion and external DTD loading. A crafted metadata file can trigger outbound network requests (SSRF), access local system resources where readable, or cause a denial of service during XML parsing.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Restriction of XML External Entity Reference

The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output.

How developers prevent this class of flaw

  • Many XML parsers and validators can be configured to disable external entity expansion.

More Improper Restriction of XML External Entity Reference vulnerabilities (CWE-611)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Patches and release notes

Third-party and government advisories

Other references

Other vulnerabilities in Bio-Formats

All Bio-Formats vulnerabilities

Recent Improper Restriction of XML External Entity Reference vulnerabilities

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