CVE-2026-34833
Bulwarkmail Webmail ≤ 1.4.10
Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/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:XSummary
CVE-2026-34833 is a high-severity Cleartext Storage of Sensitive Information (CWE-312) vulnerability in Bulwarkmail Webmail. Its CVSS base score is 8.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Credentials In Files (T1552.001); ranked at the 7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SC-28 (Protection of Information at Rest) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-34833 affects Bulwark Webmail, a self-hosted webmail client for Stalwart Mail Server, in versions prior to 1.4.10. The vulnerability resides in the GET /api/auth/session endpoint, which includes the user's plaintext password in the JSON response. This flaw, classified under CWE-312 (Cleartext Storage of Sensitive Information), carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N), indicating high confidentiality impact due to exposure of credentials in browser logs, local caches, and network proxies.
Attackers can exploit this vulnerability remotely without authentication, privileges, or user interaction, as long as they can observe the API response. Potential exploitation includes capturing plaintext passwords via network interception (e.g., man-in-the-middle attacks on proxies), accessing browser developer tools or storage on compromised client devices, or reviewing logs in environments with shared access. Successful exploitation enables credential theft, potentially leading to unauthorized access to email accounts or further lateral movement within the mail server ecosystem.
The issue has been addressed in Bulwark Webmail version 1.4.10, as detailed in the project's release notes and security advisory. Security practitioners should upgrade to this patched version immediately and review logs for evidence of prior exposure. Relevant resources include the GitHub release page at https://github.com/bulwarkmail/webmail/releases/tag/1.4.10 and the advisory at https://github.com/bulwarkmail/webmail/security/advisories/GHSA-47pm-883h-885r.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-18530
Vulnerability Data
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.…
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This issue has been patched in version 1.4.10.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 4 hardening rules · 3 OS baselines
V14.2.8
Mitigating Controls (NIST 800-53 r5) AI
SC-28 requires cryptographic or equivalent protection of sensitive data at rest, directly stopping cleartext storage in accessible resources.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Encryption and cryptographic controls for data-at-rest directly prevent cleartext storage of sensitive information.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Requiring non-standard deletion or physical destruction of media ensures that sensitive information is not left in cleartext on discarded or repurposed equipment.
Secure deletion of data before device transfer prevents residual sensitive information from remaining in cleartext on storage media that leave organizational control.
Secure deletion of obsolete or temporary copies prevents sensitive data from remaining in cleartext on disk after its intended lifetime.
Substituting real values with hashes or encrypted tokens before storage reduces the quantity of cleartext sensitive information that ends up persisted on disk.
When clear-text sensitive data is detected leaving controlled storage, the control can block the transfer, thereby limiting the exposure that would result from unencrypted storage on external media or cloud services.
By insisting that any retained test copies be stored securely and only for testing, the control reduces the likelihood that clear-text operational data will persist on disk or in backups.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (1 rule)
- V-248525 All OL 8 local disk partitions must implement cryptographic mechanisms to prevent unauthorized disclosure or modification of all information that requires at-rest protection. prevents CWE-312
Oracle Linux 9 (1 rule)
- V-271756 OL 9 local disk partitions must implement cryptographic mechanisms to prevent unauthorized disclosure or modification of all information that requires at rest protection. prevents CWE-312
RHEL 8 (1 rule)
- V-230224 All RHEL 8 local disk partitions must implement cryptographic mechanisms to prevent unauthorized disclosure or modification of all information that requires at rest protection. prevents CWE-312