Otrs2:
Affects otrs2Source GCVE Database
Not known to be exploited · CVSS 9.5 Critical.
Data as of 28 Oct 2026, 22:28 UTC
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/AU:Y/R:U/RE:L/U:RedExploitation evidence
Disclosed: evidence found.
CVE published 15 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10znunypkg:deb/ubuntu/znuny?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSznunypkg:deb/ubuntu/znuny?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSznunypkg:deb/ubuntu/znuny?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSotrs2pkg:deb/ubuntu/otrs2?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 20.04 LTSotrs2pkg:deb/ubuntu/otrs2?arch=source&distro=focalOther threats | Affected
| Fixed in– |
Ubuntu 18.04 LTSotrs2pkg:deb/ubuntu/otrs2?arch=source&distro=bionicOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In Znuny through 7.3.6, an attacker can bypass specific standard login procedures and gain unauthorized access to sensitive system functions by manipulating a specific HTTP request header. Because the application incorrectly trusts this header, an attacker can impersonate any user, including administrators, without requiring a password. This grants full access to confidential data and system controls. More specifically, the HTTPBasicAuth modules for the agent (Kernel::System::Auth::HTTPBasicAuth) and customer (Kernel::System::CustomerAuth::HTTPBasicAuth) interfaces read the username to log in not only from $ENV{REMOTE_USER} (set by the web server after successful authentication), but also, as a fallback, from $ENV{HTTP_REMOTE_USER}, which is populated directly from an attacker-controllable "Remote-User" request header. On systems where HTTPBasicAuth was configured as the authentication backend, this allowed an attacker to log in as any existing user by sending a request with a forged Remote-User header, without providing any credentials.