CVE-2026-104658
Reliance on Untrusted Inputs in a Security Decision in hMailServer
02 Description
Reliance on Untrusted Inputs in a Security Decision in hMailServer
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.
- EPSS probability
- 0.11% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 1.4% of scored records. A rank, not a probability.
- NVD base score
- 7.8 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- NVD analysis status
- Deferred. NVD last modified this record on 2026-10-08.
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2026-10-08 10:52Z20 DAYS AGO
- Last updated
- 2026-10-08 17:35Z20 DAYS AGO
- Reserved
- 2026-10-02
- Assigning CNA
- GitLab
- Record state
- PUBLISHED
- Severity
- High (CVSS 7.8)
- CNA CVSS vector
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weaknesses
- CWE-807Reliance on Untrusted Inputs in a Security DecisionBase
- Data version
- 5.2
- Document digest
- f67c728de82bfe809b324d2282545222e5b4eaedd39e9d98c0b6726c2844b654
05 Affected products
06 References
07 Remediation
Upgrade to hMailServer 6.3.6, whose helper takes the unit and the AppImage only from its own root-owned command line, refuses an AppImage request where that names none, confirms that the server has stopped, and verifies, runs and installs only copies it made after the stop, readable by root alone until they have verified. Install 6.3.6 with the package manager (apt or dnf) rather than through the live update. An AppImage run under the path unit keeps the helper script copied to /usr/lib/hmailserver/ when its update units were installed, which the AppImage's own update does not replace: copy 6.3.6's script there and give it --image in a drop-in for hmailserver-update.service. Until then: systemctl disable --now hmailserver-update.path, which turns the apply off while the update check and download go on. Windows, builds with -DHM_LIVE_UPDATE=OFF and the container image are not affected.