Vulnerability · Published Oct 2, 2026 · Assigned by NCSC.ch
CVE-2026-104733User Impersonation/Authorization Bypass in XMPP Server ejabberd
High 7.4
In plain English
A high-severity authentication bypass by spoofing in ejabberd from ProcessOne. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 4.0)7.4High
Exploit odds (30 days)0.2%top 88.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
User Impersonation in ProcessOnes XMMP Server ejabberd <= 26.04 allows an attacker to impersonate arbitrary users via unvalidated authzid parameter in SASL-PLAIN mechanism.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | ejabberd | no fix listed | DEBIAN-CVE-2026-104733 |
| Debian:13 | ejabberd | no fix listed | DEBIAN-CVE-2026-104733 |
| Debian:14 | ejabberd | 26.07-1 | DEBIAN-CVE-2026-104733 |
| Ubuntu:22.04:LTS | ejabberd | no fix listed | UBUNTU-CVE-2026-104733 |
| Ubuntu:24.04:LTS | ejabberd | no fix listed | UBUNTU-CVE-2026-104733 |
| Ubuntu:26.04:LTS | ejabberd | no fix listed | UBUNTU-CVE-2026-104733 |
| Ubuntu:26.10 | ejabberd | no fix listed | UBUNTU-CVE-2026-104733 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| ProcessOne | ejabberd | 0 – through 26.04 |
Weakness: CWE-290 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:H/SC:H/SI:H/SA:H/E:P
References
- https://www.nsideattacklogic.de/advisories/NSIDE-SA-2026-004/ third-party-advisory
- https://github.com/processone/ejabberd/releases#release-26.07 release-notes