CyberSecBulletin
CVE-2026-34833NVD status: Analyzed

webmail: Cleartext Storage of Sensitive Information

CVE-2026-34833 is a high-severity cleartext storage of sensitive information vulnerability in webmail from Bulwarkmail, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected webmail versions: < 1.4.10. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.17% 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 webmail you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Bulwarkmailwebmail< 1.4.10Not 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
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
NoneNothing can be modified.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 4.08.7HighCNA (github.com)
CVSS 3.17.5HighNVD

Official description

Bulwark Webmail is a self-hosted webmail client for Stalwart Mail Server. Prior to version 1.4.10, the GET /api/auth/session endpoint previously included the user's plaintext password in the JSON response. This exposed credentials to browser logs, local caches, and network proxie. This issue has been patched in version 1.4.10.

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

The underlying weakness: Cleartext Storage of Sensitive Information

The product stores sensitive information in cleartext within a resource that might be accessible to another control sphere.

How developers prevent this class of flaw

  • When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to encrypt the data at rest.
  • In some systems/environments such as cloud, the use of double encryption (at both the software and hardware layer) might be required, and the developer might be solely responsible for both layers, instead of shared responsibility with the administrator of the broader system/environment.

More Cleartext Storage of Sensitive Information vulnerabilities (CWE-312)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in webmail

All webmail vulnerabilities

Recent Cleartext Storage of Sensitive Information vulnerabilities

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