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NVD / CVE Program· CNA GitHub_M

CVE-2026-43914: Vaultwarden: Brute-force protection bypass vulnerability

Noroxi assessment

Priority: Monitor (action score 39/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.28% (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: dani-garcia vaultwarden 1.35.4.
  • Severity is disputed: the assigning authority (CNA) scores it 7.3, NVD 9.8.

Low priority for now. Upgrade to dani-garcia vaultwarden 1.35.4 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

Vaultwarden is a Bitwarden-compatible server written in Rust. Prior to 1.35.4, there is a security vulnerability in Vaultwarden that allows bypassing the login brute-force protection if email 2fa is enabled. If email 2fa is enabled, the unprotected 2fa-function send_email_login (email.rs, api endpoint /api/two-factor/send-email-login) also acts as an oracle determining whether a username-password combination is correct. An attacker can abuse that endpoint to brute-force passwords without rate-limiting. This works even for users who don't have email 2fa configured. This vulnerability is fixed in 1.35.4.

CriticalCVSS 9.8 · v3.1—Proof of concept Fix available
Published
May 11, 2026
Updated
Oct 26, 2026
EPSS
0.2% · 21th percentile

Report tools

JSON

Action score

39

Monitor

Low priority for now.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
proof of concept
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
9.8
CNA · GitHub_M
7.3
2.5 point gap

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

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
  • Proof of concept exists, no weaponized module
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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.

VendorProduct
dani-garciavaultwarden

Affected versions

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

  • dani-garcia vaultwardenbefore 1.35.4

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.

  • dani-garcia vaultwarden

    • < 1.35.4affected

Same product

dani-garcia: all records

Other highest-scoring records for the same primary product.

  • CVE-2024-55225An issue in the component src/api/identity.rs of Vaultwarden prior to v1.32.5 allows attackers to impersonate users, including Administrator
    39Monitor
  • CVE-2024-39924An issue was discovered in Vaultwarden (formerly Bitwarden_RS) 1.30.3.
    39Monitor
  • CVE-2024-55224An HTML injection vulnerability in Vaultwarden prior to v1.32.5 allows attackers to execute arbitrary code via injecting a crafted payload i
    38Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-43912May 11, 2026 · Vaultwarden: Cross-Org Group Binding Enables Unauthorized Read And Write Access Into Another Organization
    34Monitor
  • ← EarlierCVE-2026-43913May 11, 2026 · Vaultwarden: Unconfirmed Owner Can Purge Entire Organization Vault
    32Monitor
  • Later →CVE-2026-47158Jul 15, 2026 · Vaultwarden: CSRF in SSO Authorization Flow
    33Monitor

Remediation

Which version to upgrade to

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

Product / packageFixed versionSource
dani-garcia vaultwarden1.35.4 · descriptionVendor (CNA)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:12026-08-24

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.

  1. Published
  2. First PoC+104 d
  3. TodayNov 9, 2026+182 d

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

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

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.

  • CVE-2026-2780168 days apartVaultwarden: 2FA Bypass on Protected Actions due to Faulty Rate Limit Enforcement
    24Monitor

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
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-307 · Improper Restriction of Excessive Authentication Attempts

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Attack context

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

Change log

  1. Fix✗ → ✓

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

References

Show all references (1 more)

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

All records