CVE-2019-11778· NVD / CVE Program· CNA eclipse

If an MQTT v5 client connects to Eclipse Mosquitto versions 1.6.0 to 1.6.4 inclusive, sets a last will and testament, sets a will delay inte

Noroxi assessment

Priority: Monitor (action score 21/100)

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: 0.76% (FIRST EPSS); higher than 54.8% of all records.
Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
Fixed version: mosquitto (Debian:12) 1.6.6-1.

Low priority for now. Upgrade to mosquitto (Debian:12) 1.6.6-1 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

If an MQTT v5 client connects to Eclipse Mosquitto versions 1.6.0 to 1.6.4 inclusive, sets a last will and testament, sets a will delay interval, sets a session expiry interval, and the will delay interval is set longer than the session expiry interval, then a use after free error occurs, which has the potential to cause a crash in some situations.

MediumCVSS 5.4 · v3.1—No exploit Fix available

Memory safety

Published: Sep 18, 2019
Updated: Jun 16, 2026
EPSS: 0.7% · 54th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 21 / 40 · 5.4 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.7%

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
eclipse	mosquitto	cpe:2.3:a:eclipse:mosquitto

Affected versions

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

eclipse mosquitto1.6 and later · before 1.6.5

Versions reported by the vendor

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

The Eclipse Foundation Eclipse Mosquitto
- 1.6.0 to 1.6.4affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:12	mosquitto	before 1.6.6-1	1.6.6-1

Same product

eclipse: all records

Other highest-scoring records for the same primary product.

CVE-2024-10525Eclipse Mosquito: Heap Buffer Overflow in my_subscribe_callback
46Plan
CVE-2018-12543In Eclipse Mosquitto versions 1.5 to 1.5.2 inclusive, if a message is published to Mosquitto that has a topic starting with $, but that is n
41Plan
CVE-2018-12551When Eclipse Mosquitto version 1.0 to 1.5.5 (inclusive) is configured to use a password file for authentication, any malformed data in the p
32Monitor

Published before and after this one in the same product

← EarlierCVE-2018-12550Mar 27, 2019 · When Eclipse Mosquitto version 1.0 to 1.5.5 (inclusive) is configured to use an ACL file, and that ACL file is empty, or contains only comme
32Monitor
← EarlierCVE-2017-7655Mar 27, 2019 · In Eclipse Mosquitto version from 1.0 to 1.4.15, a Null Dereference vulnerability was found in the Mosquitto library which could lead to cra
31Monitor
Later →CVE-2019-11779Sep 19, 2019 · In Eclipse Mosquitto 1.5.0 to 1.6.5 inclusive, if a malicious MQTT client sends a SUBSCRIBE packet containing a topic that consists of appro
27Monitor

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
debian:mosquitto	1.6.6-1 · Debian:12	Package registry (OSV)

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.
A low-privileged account is enough.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: none
Integrity: low · data or configuration can be modified
Availability: low · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: None
Integrity impact: Low
Availability impact: Low

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

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

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

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

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

Attack context

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

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

Fix✗ → ✓Sep 28, 2026, 10:48 PM UTC

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

References

bugs.eclipse.org/bugs/show_bug.cgi?id=551162

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

All records