CVE-2026-88859
Description
A flaw was found in Evolution. A remote attacker can exploit this vulnerability by sending a specially crafted HTML email containing a spoofed vCard control. When a victim clicks on this control, Evolution's trusted JavaScript handler incorrectly assigns an attacker-controlled JavaScript URL to an iframe's source. This action leads to arbitrary JavaScript execution within the mail-viewing context, effectively bypassing the security measures designed to prevent script execution in email content.
Mitigation
To mitigate this issue, users can disable JavaScript execution for HTML mail in Evolution. This can be done through the Evolution preferences or by using `gsettings`. Disabling JavaScript may affect the rendering and functionality of some legitimate HTML emails.
To disable JavaScript via `gsettings`, execute the following command:
`gsettings set org.gnome.evolution.mail enable-javascript false`
To revert this change, execute:
`gsettings set org.gnome.evolution.mail enable-javascript true`
Note that changes to `gsettings` take effect immediately, but Evolution may need to be restarted for the setting to be fully applied to already open mail views.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.3 | N/A | 6.3 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | Low | N/A | Low |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | Low | N/A | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
Understanding the Weakness (CWE)
Integrity
Technical Impact: Unexpected State
Acknowledgements
Red Hat would like to thank Jurre van Bergen for reporting this issue.
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