CyberSecBulletin
CVE-2026-9592NVD status: Deferred

SEPPmail Secure Email Gateway & SEPPmail Cloud: Use of HTTP Request With Sensitive Query String

CVE-2026-9592 is a high-severity use of HTTP request with sensitive query string vulnerability in SEPPmail Secure Email Gateway & SEPPmail Cloud from SeppMail, with a CVSS 4.0 base score of 7.5 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.24% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of SEPPmail Secure Email Gateway & SEPPmail Cloud you run against the affected versions below, and install the vendor's latest release.

Affected products and versions

VendorProductAffected versionsFixed in
SEPPmailSEPPmail Secure Email Gateway & SEPPmail CloudNot specified in the recordNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
AdjacentThe attacker must be on the same local network segment.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Attack requirements
NoneThe attack does not depend on a particular deployment or configuration.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Confidentiality (vulnerable system)
HighSerious loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
HighSerious loss of integrity on the vulnerable system.
Availability (vulnerable system)
NoneNo loss of availability on the vulnerable system.
Confidentiality (other systems)
HighSerious loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
HighSerious loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
NoneNo loss of availability on systems beyond the vulnerable one.

Vector: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA (ncsc.ch).

Official description

SEPPmail Secure Email Gateway & SEPPmail Cloud before version 15.0.4.2 allows an attacker to replay & hijack a user session in the GINA web portal, as the session token is disclosed inside the URL and a HTTP header.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Use of HTTP Request With Sensitive Query String

The web application uses an HTTP method to process a request, but the request includes sensitive information in the query string.

How developers prevent this class of flaw

  • When sending sensitive information, only include it in the request body or request headers instead of the query string. This may require avoiding use of GET requests.

More Use of HTTP Request With Sensitive Query String vulnerabilities (CWE-598)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Use of HTTP Request With Sensitive Query String vulnerabilities

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