NVD / CVE Program· CNA GitHub_M

CVE-2026-34834: Bulwark Webmail: Authentication Bypass in verifyIdentity() due to missing cookie validation

Noroxi assessment

Priority: Monitor (action score 34/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.25% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: bulwarkmail webmail 1.4.10.

Low priority for now. Upgrade to bulwarkmail webmail 1.4.10 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Bulwark Webmail is a self-hosted webmail client for Stalwart Mail Server. Prior to version 1.4.10, the verifyIdentity() function contained logic that returned true if no session cookies were present. This allowed unauthenticated attackers to bypass security checks and access/modify user settings via the /api/settings endpoint by providing arbitrary headers. This issue has been patched in version 1.4.10.

HighCVSS 8.7 · v4.0—No exploit Fix available

Published: Apr 2, 2026
Updated: Jul 24, 2026
EPSS: 0.2% · 16th percentile
CWE: CWE-287

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 34 / 40 · 8.7 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · GitHub_M: 8.7; NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
bulwarkmail	webmail	cpe:2.3:a:bulwarkmail:webmail

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

bulwarkmail webmailbefore 1.4.10

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

bulwarkmail webmail
- < 1.4.10affected

Same product

bulwarkmail: all records

Other highest-scoring records for the same primary product.

CVE-2026-35391Bulwark Webmail getClientIP() trusted client-controlled X-Forwarded-For value, enabling rate limit bypass and audit log forgery
34Monitor
CVE-2026-35389Bulwark Webmail S/MIME signature verification accepted self-signed certificates
34Monitor
CVE-2026-34833Bulwark Webmail: Information Exposure: password returned in /api/auth/session
34Monitor

Published before and after this one in the same product

Later →CVE-2026-35390Apr 6, 2026 · Content-Security-Policy was set to Report-Only mode, failing to block XSS attacks
21Monitor
Later →CVE-2026-113728Oct 20, 2026 · Bulwark Webmail: DNS-rebinding SSRF in public iCalendar fetch endpoint
30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
bulwarkmail webmail	1.4.10 · description	Vendor (CNA)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: X

Weakness class (CWE)

CWE-287 · Improper Authentication

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/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:X

nvd-secondary

Root cause

Authentication is added route by route instead of being enforced in one place. When a route added later bypasses the shared middleware, the session check never runs for it.

The bug in code

The whole CWE-287 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1app.use("/admin", requireSession, adminRouter);
2

3// Route added later skips the middleware
4app.post("/admin-api/config", updateConfig);

Fixed

1const admin = express.Router();
2admin.use(requireSession, requireRole("admin"));
3

4admin.post("/config", updateConfig);
5app.use("/admin", admin);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

Change log

Fix✗ → ✓Sep 29, 2026, 11:55 AM UTC

For records you follow, these changes also arrive as notifications. →

References

github.com/bulwarkmail/webmail/releases/tag/1.4.10

Show all references (1 more)

github.com/bulwarkmail/webmail/security/advisories/GHSA-4356-876g-rfmh

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records