CVE-2026-24031: Dovecot SQL based authentication can be bypassed when auth_username_chars is cleared by admin.
Noroxi assessment
Priority: Monitor (action score 32/100)
- Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.40% (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.
- Fixed version: dovecot (Alpine:v3.23) 2.4.3-r0; dovecot (Debian:13) 1:2.4.1+dfsg1-6+deb13u4; dovecot (Debian:14) 1:2.4.3+dfsg1-1.
Low priority for now. Upgrade to dovecot (Alpine:v3.23) 2.4.3-r0; dovecot (Debian:13) 1:2.4.1+dfsg1-6+deb13u4; dovecot (Debian:14) 1:2.4.3+dfsg1-1 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
Dovecot SQL based authentication can be bypassed when auth_username_chars is cleared by admin. This vulnerability allows bypassing authentication for any user and user enumeration. Do not clear auth_username_chars. If this is not possible, install latest fixed version. No publicly available exploits are known.
- Published
- Mar 27, 2026
- Updated
- Oct 26, 2026
- EPSS
- 0.4% · 34th percentile
- CWE
- CWE-89
Report tools
Action score
32
Monitor
Low priority for now.
- CVSS
- 32 / 40 · 8.2 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 8.2
- CNA · OX
- 7.7
- 0.5 point gap
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/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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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.
We use this product, ask for helpAffected 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 |
|---|---|---|
| dovecot | dovecot | cpe:2.3:a:dovecot:dovecot |
| open-xchange | dovecot | cpe:2.3:a:open-xchange:dovecot |
Using dovecot? Add it to your stack and be the first to know about CVEs like this one. (Email server)
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- dovecot dovecotbefore 2.4.3
- open-xchange dovecotbefore 3.1.4
Versions reported by the vendor
Affected version ranges reported by the assigning authority (OX). Independent of NVD's CPE analysis and usually ahead of it.
Open-Xchange GmbH OX Dovecot Pro
- up to and including 3.1.0affected · semver
- up to and including 2.4.0affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Alpine:v3.23 | dovecot | before 2.4.3-r0 | 2.4.3-r0 |
| Debian:13 | dovecot | before 1:2.4.1+dfsg1-6+deb13u4 | 1:2.4.1+dfsg1-6+deb13u4 |
| Debian:14 | dovecot | before 1:2.4.3+dfsg1-1 | 1:2.4.3+dfsg1-1 |
| openSUSE:Leap 16.0 | dovecot24 | before 2.4.3-160000.1.1 | 2.4.3-160000.1.1 |
| openSUSE:Tumbleweed | dovecot24 | before 2.4.3-1.1 | 2.4.3-1.1 |
| SUSE:Linux Enterprise Server 16.0 | dovecot24 | before 2.4.3-160000.1.1 | 2.4.3-160000.1.1 |
Same product
dovecot: all recordsOther highest-scoring records for the same primary product.
- CVE-2019-11500In Dovecot before 2.2.36.4 and 2.3.x before 2.3.7.2 (and Pigeonhole before 0.5.7.2), protocol processing can fail for quoted strings.58Plan
- CVE-2020-7046lib-smtp in submission-login and lmtp in Dovecot 2.3.9 before 2.3.9.3 mishandles truncated UTF-8 data in command parameters, as demonstrated45Plan
- CVE-2016-8652The auth component in Dovecot before 2.2.27, when auth-policy is configured, allows a remote attackers to cause a denial of service (crash) 37Monitor
Published before and after this one in the same product
- ← EarlierCVE-2025-59032Mar 27, 2026 · ManageSieve AUTHENTICATE command crashes when using literal as SASL initial response.30Monitor
- ← EarlierCVE-2026-0394Mar 27, 2026 · When dovecot has been configured to use per-domain passwd files, and they are placed one path component above /etc, or slash has been added 21Monitor
- Later →CVE-2026-27855Mar 27, 2026 · Dovecot OTP authentication is vulnerable to replay attack under specific conditions.23Monitor
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 |
|---|---|---|
| alpine:dovecot | 2.4.3-r0 · Alpine:v3.23 | Package registry (OSV) |
| debian:dovecot | 1:2.4.1+dfsg1-6+deb13u4 · Debian:13 | Package registry (OSV) |
| opensuse:dovecot24 | 2.4.3-1.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| suse:dovecot24 | 2.4.3-160000.1.1 · SUSE:Linux Enterprise Server 16.0 | Package registry (OSV) |
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.
| Source | Kind | Date |
|---|---|---|
| Proof-of-concept repository on GitHub | stars:2 | 2026-08-12 |
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.
- Published
- First PoC+138 d
- TodayOct 29, 2026+216 d
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 researchersFinders, 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
- low · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- none
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- Low
- Integrity impact
- High
- Availability impact
- None
Weakness class (CWE)
CWE-89 · Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
nvd-primary
Root cause
The query text is built by concatenating user input. The database cannot tell where the data ends and the command begins.
The bug in code
The whole CWE-89 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
const owner = req.query.owner;
const rows = await db.query(
"SELECT * FROM files WHERE owner = '" + owner + "'"
);Fixed
const owner = req.query.owner;
const rows = await db.query(
"SELECT * FROM files WHERE owner = $1",
[owner]
);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)
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Object Relational Mapping InjectionCAPEC-109likelihood: Low · High
- SQL Injection through SOAP Parameter TamperingCAPEC-110likelihood: High · Very High
- Expanding Control over the Operating System from the DatabaseCAPEC-470Very High
- SQL InjectionCAPEC-66likelihood: High · High
- Blind SQL InjectionCAPEC-7likelihood: High · High
ATT&CK techniques
—
Change log
- Fix✗ → ✓
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References
Show all references (3 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.