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Findings

CVE-2026-110777

A flaw was found in evolution-data-server.

Published Oct 14, 2026 · corrected/updated Oct 16, 2026 · Red Hat Red Hat Enterprise Linux 10 · evidence confidence high

A flaw was found in evolution-data-server. Calendar events containing a file:// URI in their ATTACH property automatically read the targeted local file, base64-encode its contents and upload it back to the server when the event is saved. There are no file path restrictions or checks to verify whether the attachment originally came from the server or was added locally. This allows an attacker with access to a shared CalDAV calendar to exfiltrate arbitrary files the user has access to when interacting with malicious calendar events.

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

CVE-2026-110777 is a medium public vulnerability record for Red Hat Red Hat Enterprise Linux 10. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether Red Hat Red Hat Enterprise Linux 10 is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: evolution-data-server (3.46.4-2, 3.46.4-2+deb12u1, 3.47.2-1); evolution-data-server (3.56.1-2, 3.56.2-0+deb13u1, 3.56.2-1); evolution-data-server (3.56.1-2, 3.56.2-1, 3.56.2-2); Red Hat Red Hat Enterprise Linux 10. Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: CVSS 5.7, EPSS 0.4%. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-200. Sources contributing to this record: cve_org, epss, nvd, osv. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Exploitation and remediation

  • Exploitation evidence

    Not listed as known exploited in CISA KEV. Not in the CISA KEV catalog.

  • Patch and remediation

    No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.

  • Safe detection guidance

    Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Technology hubs

Debian

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 14, 2026 · NIST NVD

    Detected

    A flaw was found in evolution-data-server. Calendar events containing a file:// URI in their ATTACH property automatically read the targeted local file, base64-encode its contents and upload it back to the server when the event is saved. There are no file path restrictions or checks to verify whether the attachment originally came from the server or was added locally. This allows an attacker with

  2. Oct 14, 2026 · NIST NVD

    Updated

    A flaw was found in evolution-data-server. Calendar events containing a file:// URI in their ATTACH property automatically read the targeted local file, base64-encode its contents and upload it back to the server when the event is saved. There are no file path restrictions or checks to verify whether the attachment originally came from the server or was added locally. This allows an attacker with

  3. Oct 14, 2026 · NIST NVD

    Updated

    A flaw was found in evolution-data-server. Calendar events containing a file:// URI in their ATTACH property automatically read the targeted local file, base64-encode its contents and upload it back to the server when the event is saved. There are no file path restrictions or checks to verify whether the attachment originally came from the server or was added locally. This allows an attacker with

  4. Oct 15, 2026 · NIST NVD

    Updated

    A flaw was found in evolution-data-server. Calendar events containing a file:// URI in their ATTACH property automatically read the targeted local file, base64-encode its contents and upload it back to the server when the event is saved. There are no file path restrictions or checks to verify whether the attachment originally came from the server or was added locally. This allows an attacker with

  5. Oct 15, 2026 · NIST NVD

    Updated

    A flaw was found in evolution-data-server. Calendar events containing a file:// URI in their ATTACH property automatically read the targeted local file, base64-encode its contents and upload it back to the server when the event is saved. There are no file path restrictions or checks to verify whether the attachment originally came from the server or was added locally. This allows an attacker with

  6. Oct 16, 2026 · OSV.dev

    Updated

    A flaw was found in evolution-data-server. Calendar events containing a file:// URI in their ATTACH property automatically read the targeted local file, base64-encode its contents and upload it back to the server when the event is saved. There are no file path restrictions or checks to verify whether the attachment originally came from the server or was added locally. This allows an attacker with

Affected

  • Debian:12 evolution-data-server3.46.4-2, 3.46.4-2+deb12u1, 3.47.2-1
  • Debian:13 evolution-data-server3.56.1-2, 3.56.2-0+deb13u1, 3.56.2-1
  • Debian:14 evolution-data-server3.56.1-2, 3.56.2-1, 3.56.2-2
  • vendor Red Hat Red Hat Enterprise Linux 10version unspecified
  • vendor Red Hat Red Hat Enterprise Linux 6version unspecified
  • vendor Red Hat Red Hat Enterprise Linux 7version unspecified
  • vendor Red Hat Red Hat Enterprise Linux 8version unspecified
  • vendor Red Hat Red Hat Enterprise Linux 9version unspecified

Sources

  • CVE.orgVulnerability recordCVE-2026-110777

    A flaw was found in evolution-data-server. Calendar events containing a file:// URI in their ATTACH property automatically read the targeted local file, base64-encode its contents and upload it back to the server when the event is saved. There are no file path restrictions or che

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-110777

    30-day exploitation probability 0.4%

    first.org
  • NIST NVDVulnerability recordCVE-2026-110777

    A flaw was found in evolution-data-server. Calendar events containing a file:// URI in their ATTACH property automatically read the targeted local file, base64-encode its contents and upload it back to the server when the event is saved. There are no file path restrictions or che

    nvd.nist.gov
  • OSV.devPackage advisoryDEBIAN-CVE-2026-110777
    osv.dev

References