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TI-2021-08534 Aliases CVE-2021-26929GHSA-qc5g-54hm-vfmc

An XSS issue was discovered in Horde Groupware Webmail Edition through 5.2.22 (where the…

Priority LOW 35CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Cross-site scripting
Confidentiality · integrity · availability
Low · Low · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-79.

Summary

An XSS issue was discovered in Horde Groupware Webmail Edition through 5.2.22 (where the Horde_Text_Filter library before 2.3.7 is used). The attacker can send a plain text e-mail message, with JavaScript encoded as a link or email that is mishandled by preProcess in Text2html.php, because bespoke use of \x00\x00\x00 and \x01\x01\x01 interferes with XSS defenses.

Why it matters now

EPSS 0.04944 92nd percentileScored 2026-11-07
Public exploit Yes 2 exploit referencesTagged by NVD
Fix No fix listed No fixed version in the sources yet

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:horde:groupware:*:*:*:*:webmail:*:*:*up to 5.2.22VulnerableHorde
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*9.0VulnerableDebian
  • cpe:2.3:a:horde:groupware:*:*:*:*:webmail:*:*:* Versions up to 5.2.22 Vulnerable ·Horde
  • cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-26929
  2. 2026-10-03 Alias added: GHSA-qc5g-54hm-vfmc

References

Exploit 2

Advisory 5

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences