CVE-2021-41036
In versions prior to 1.1 of the Eclipse Paho MQTT C Client, the client does not check rem_len...
In versions prior to 1.1 of the Eclipse Paho MQTT C Client, the client does not check rem_len size in readpacket.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
In versions prior to 1.1 of the Eclipse Paho MQTT C Client, the client does not check rem_len size in readpacket.
- Record
CVE-2021-41036- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-787
- Updated
- 2026-11-02
CVE List No score
In versions prior to 1.1 of the Eclipse Paho MQTT C Client, the client does not check rem_len size in readpacket.
- Record
CVE-2021-41036- Weakness
- CWE-787
- Updated
- 2026-11-02
EUVDEUVD-2021-28189 No score
In versions prior to 1.1 of the Eclipse Paho MQTT C Client, the client does not check rem_len size in readpacket.
- Record
EUVD-2021-28189- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-m9hg-v7xv-429h No score
In versions prior to 1.1 of the Eclipse Paho MQTT C Client, the client does not check rem_len...
In versions prior to 1.1 of the Eclipse Paho MQTT C Client, the client does not check rem_len size in readpacket.
- Record
GHSA-m9hg-v7xv-429h- Weakness
- CWE-787
- Updated
- 2026-11-02
OSV
In versions prior to 1.1 of the Eclipse Paho MQTT C Client, the client does not check rem_len size in readpacket.
- Record
CVE-2021-41036- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-41036
In versions prior to 1.1 of the Eclipse Paho MQTT C Client, the client does not check rem_len size in readpacket.
- Record
UBUNTU-CVE-2021-41036- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
paho.mqtt.cUbuntu:22.04:LTS |
All versions, plus listed versions 1.3.9-11.3.9-1build1 |
None known |
paho.mqtt.cUbuntu:24.04:LTS |
All versions, plus listed versions 1.3.12-11.3.13-11.3.13-1build11.3.13-1build2 |
None known |
paho.mqtt.cUbuntu:25.10 |
All versions, plus listed versions 1.3.14-2 |
None known |
paho.mqtt.cUbuntu:26.10 |
All versions, plus listed versions 1.3.15-11.3.16+ds-11.3.16+ds-1build1 |
None known |
paho.mqtt.cUbuntu:26.04:LTS |
All versions, plus listed versions 1.3.14-21.3.15-1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-41036 is a critical vulnerability (CVSS 9.8) in The Eclipse Foundation Eclipse Paho Mqtt C Client, published November 2, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.21%, the 68th percentile. No source names a fixed version.