Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') in hMailServer
Affects hMailServer 6.0.0-B1 through 6.2.18, on Windows only. No vendor rating is given; CVSS scores it 8.8 (high). Fixed in 6.2.19.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 6.2.19
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Affects hMailServer versions 6.0.0-B1 through 6.2.18. Windows only in these versions.
- Published
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 17/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
SQL injection in Progressive Robot Ltd's hMailServer, when it runs on MySQL/MariaDB or PostgreSQL, lets a remote attacker alter the SQL statements the server runs, with the privileges of the database account. In the default setup, a logged-in user who is allowed to send mail can trigger it by sending to an address of their choosing.
Read the original description
SQL injection in the database layer of Progressive Robot hMailServer 6.0.0-B1 through 6.2.18, when the server uses MySQL/MariaDB or PostgreSQL, allows a remote attacker to alter SQL statements the server runs. On those two engines parameters are not bound: SQLStatement::GenerateFromCommand wrote each value into the statement's text as a quoted literal with a separate string replacement over the whole text per parameter, so a value holding the name of a parameter substituted after it had that name replaced, inside the value, by the later value with its own quotes, which ended the literal early and placed the later value in the statement as SQL. The row the server writes for each recipient of a queued message carries the recipient's address twice, so in the default configuration an authenticated user who may send mail reaches it by sending to an address of their choosing. A remote unauthenticated sender reaches the same statement through a message the server sends to the envelope sender, such as a delivery failure notice or an automatic reply, and, when greylisting or message indexing is enabled (both are off by default), through the greylisting record's envelope addresses or through the message metadata the server stores for IMAP SORT, which carries four header fields of a received message. An altered statement runs with the privileges of the server's database account; on PostgreSQL, whose client call runs every statement in the text it is given, further statements can follow it, while on MySQL/MariaDB, where one statement is run per call, the change is confined to the statement it is in. SQL Server and SQL Server Compact, where parameters are bound, are not affected.
Who should check
Teams running Progressive Robot hMailServer 6.0.0-B1 through 6.2.18 on Windows with MySQL/MariaDB or PostgreSQL as the database engine.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure8/25Specific setups only, reachable over the network
- Reach?/20Unknown. No tracked technology or package matched
- Severity8.8/10CVSS 8.8
- No patch0/5No signal
What would change the score
- Would score about 67 if added to CISA KEV
- Would score about 62 if CISA's SSVC rates exploitation active
- Would score about 24 if CISA's SSVC rates it automatable
What to do
Check whether your setup matches what the bug needs.
Affects hMailServer versions 6.0.0-B1 through 6.2.18. Windows only in these versions.Upgrade to a fixed version: 6.2.19.
Workaround: Keep message indexing (MessageIndexing) and greylisting off; this removes those two paths only and is not a complete workaround.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-126617 (Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') in hMailServer), using the cve.now data below.
Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.
What cve.now has for CVE-2026-126617 (entry last updated 2026-11-11):
Affected:
- Progressive Robot Ltd hMailServer: from 6.0.0-B1, through 6.2.18
Fixed versions: 6.2.19.
Conditions (all must be true for the bug to be hit):
- Affects hMailServer versions 6.0.0-B1 through 6.2.18. (source: https://gitlab.com/hmailserver/hmailserver/-/work_items/101)
- Windows only in these versions. (source: https://gitlab.com/hmailserver/hmailserver/-/work_items/101)
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
Attacker needs: network access, low-privilege login, no user action.
Workaround: Keep message indexing (MessageIndexing) and greylisting off; this removes those two paths only and is not a complete workaround. (source: https://www.cve.org/CVERecord?id=CVE-2026-126617)
CISA KEV: CVE-2026-126617 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-126617 only. If you also check another CVE, look up its own KEV status; never assume it from this one.
How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.
Verify against the linked advisories before concluding, and cite the date you read each one:
- https://gitlab.com/hmailserver/hmailserver/-/work_items/101
- https://gitlab.com/hmailserver/hmailserver/-/releases/v6.2.19
- https://www.cve.org/CVERecord?id=CVE-2026-126617
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.
Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.
Entry: https://cve.now/CVE-2026-126617
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id CVE-2026-126617.Timeline
- CVE published
- First seen by cve.now
Affected versions
- Progressive Robot Ltd hMailServer
From 6.0.0-B1 · through 6.2.18
Evidence 4
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-126617
Is CVE-2026-126617 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
The flaw is an SQL injection bug: special characters in input are not properly neutralized before they are used in a database command, so the input can change how that command runs.Source: gitlab.com, cve.org
Which versions are affected by CVE-2026-126617?
hMailServer: from 6.0.0-B1 through 6.2.18.Source: cve.now feed data
Am I affected, and how do I check?
Versions 6.0.0-B1 through 6.2.18 on Windows are listed as affected. To check a installation, look up the installed hMailServer version and confirm the operating system is Windows.Source: gitlab.com, cve.org
How do I fix CVE-2026-126617?
Upgrade to hMailServer 6.2.19 or later. Until then, keep message indexing (MessageIndexing) and greylisting off, which removes two affected paths but is not a complete workaround.Source: gitlab.com, cve.org
Why do the sources disagree?
The description says the flaw can be reached without authentication, but the CVSS vector lists privileges required as Low (PR:L), which implies an account is needed. The sources conflict on this point and the facts do not settle it.Source: gitlab.com, cve.org