CVE-2026-5246
Cesanta Mongoose P-384 Public Key mongoose.c mg_tls_verify_cert_signature authorization
A vulnerability was determined in Cesanta Mongoose up to 7.20. Affected is the function mg_tls_verify_cert_signature of the file mongoose.c of the component P-384 Public Key Handler. Executing a manipulation can lead to authorization bypass. The attack can be executed remotely. Attacks of this nature are highly complex. The exploitability is told to be difficult. The exploit has been publicly disclosed and may be utilized. Upgrading to version 7.21 is able to address this issue. This patch is called 0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1. The affected component should be upgraded. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
6.3
Cesanta Mongoose P-384 Public Key mongoose.c mg_tls_verify_cert_signature authorization
A vulnerability was determined in Cesanta Mongoose up to 7.20. Affected is the function mg_tls_verify_cert_signature of the file mongoose.c of the component P-384 Public Key Handler. Executing a manipulation can lead to authorization bypass. The attack can be executed remotely. Attacks of this nature are highly complex. The exploitability is told to be difficult. The exploit has been publicly disclosed and may be utilized. Upgrading to version 7.21 is able to address this issue. This patch is called 0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1. The affected component should be upgraded. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.
- Record
CVE-2026-5246- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P - CVSS 3.1
- 5.6 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C - CVSS 3.0
- 5.6 Medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C - CVSS 2.0
- 5.1
AV:N/AC:H/Au:N/C:P/I:P/A:P/E:POC/RL:OF/RC:C - Weakness
- CWE-639, CWE-285
- Updated
- 2026-11-02
EUVDEUVD-2026-18184
6.3
A vulnerability was determined in Cesanta Mongoose up to 7.20. Affected is the function mg_tls_verify_cert_signature of the file mongoose.c of the component P-384 Public Key Handler. Executing a manipulation can lead to authorization bypass. The attack can be executed remotely. Attacks of this nature are highly complex. The exploitability is told to be difficult. The exploit has been publicly disclosed and may be utilized. Upgrading to version 7.21 is able to address this issue. This patch is called 0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1. The affected component should be upgraded. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.
- Record
EUVD-2026-18184- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-hm7q-jq63-pr78
2.9
A vulnerability was determined in Cesanta Mongoose up to 7.20. Affected is the function...
A vulnerability was determined in Cesanta Mongoose up to 7.20. Affected is the function mg_tls_verify_cert_signature of the file mongoose.c of the component P-384 Public Key Handler. Executing a manipulation can lead to authorization bypass. The attack can be executed remotely. Attacks of this nature are highly complex. The exploitability is told to be difficult. The exploit has been publicly disclosed and may be utilized. Upgrading to version 7.21 is able to address this issue. This patch is called 0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1. The affected component should be upgraded. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.
- Record
GHSA-hm7q-jq63-pr78- CVSS 4.0
- 2.9 Low
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 5.6 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L - Weakness
- CWE-285
- Updated
- 2026-11-02
NVD
2.9
A vulnerability was determined in Cesanta Mongoose up to 7.20. Affected is the function mg_tls_verify_cert_signature of the file mongoose.c of the component P-384 Public Key Handler. Executing a manipulation can lead to authorization bypass. The attack can be executed remotely. Attacks of this nature are highly complex. The exploitability is told to be difficult. The exploit has been publicly disclosed and may be utilized. Upgrading to version 7.21 is able to address this issue. This patch is called 0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1. The affected component should be upgraded. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.
- Record
CVE-2026-5246- CVSS 4.0
- 2.9 Low
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 5.6 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L - CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 5.1 Medium
AV:N/AC:H/Au:N/C:P/I:P/A:P - Weakness
- CWE-285, CWE-639
- Updated
- 2026-11-02
OSV
2.9
Cesanta Mongoose P-384 Public Key mongoose.c mg_tls_verify_cert_signature authorization
A vulnerability was determined in Cesanta Mongoose up to 7.20. Affected is the function mg_tls_verify_cert_signature of the file mongoose.c of the component P-384 Public Key Handler. Executing a manipulation can lead to authorization bypass. The attack can be executed remotely. Attacks of this nature are highly complex. The exploitability is told to be difficult. The exploit has been publicly disclosed and may be utilized. Upgrading to version 7.21 is able to address this issue. This patch is called 0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1. The affected component should be upgraded. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.
- Record
CVE-2026-5246- CVSS 4.0
- 2.9 Low
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P - Weakness
- CWE-285, CWE-639
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-5246
8.1
A vulnerability was determined in Cesanta Mongoose up to 7.20. Affected is the function mg_tls_verify_cert_signature of the file mongoose.c of the component P-384 Public Key Handler. Executing a manipulation can lead to authorization bypass. The attack can be executed remotely. Attacks of this nature are highly complex. The exploitability is told to be difficult. The exploit has been publicly disclosed and may be utilized. Upgrading to version 7.21 is able to address this issue. This patch is called 0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1. The affected component should be upgraded. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.
- Record
DEBIAN-CVE-2026-5246- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVJLSEC-2026-371
2.9
A vulnerability was determined in Cesanta Mongoose up to 7.20
A vulnerability was determined in Cesanta Mongoose up to 7.20. Affected is the function mg_tls_verify_cert_signature of the file mongoose.c of the component P-384 Public Key Handler. Executing a manipulation can lead to authorization bypass. The attack can be executed remotely. Attacks of this nature are highly complex. The exploitability is told to be difficult. The exploit has been publicly disclosed and may be utilized. Upgrading to version 7.21 is able to address this issue. This patch is called 0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1. The affected component should be upgraded. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.
- Record
JLSEC-2026-371- CVSS 4.0
- 2.9 Low
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 2.0
- 5.1 Medium
AV:N/AC:H/Au:N/C:P/I:P/A:P - CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-5246
2.9
A vulnerability was determined in Cesanta Mongoose up to 7.20. Affected is the function mg_tls_verify_cert_signature of the file mongoose.c of the component P-384 Public Key Handler. Executing a manipulation can lead to authorization bypass. The attack can be executed remotely. Attacks of this nature are highly complex. The exploitability is told to be difficult. The exploit has been publicly disclosed and may be utilized. Upgrading to version 7.21 is able to address this issue. This patch is called 0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1. The affected component should be upgraded. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.
- Record
UBUNTU-CVE-2026-5246- CVSS 4.0
- 2.9 Low
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P - CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 3.1
- 5.6 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
swupdateDebian:12 |
All versions, plus listed versions 2022.12+dfsg-42022.12+dfsg-4+deb12u12022.12+dfsg-4+deb12u1~bpo11+12022.12+dfsg-4+deb12u22022.12+dfsg-4+deb12u3 Show 45 moreShow less2023.05+dfsg-12023.05+dfsg-22023.05+dfsg-2~bpo12+12023.05+dfsg-32023.05+dfsg-42023.05+dfsg-52023.05+dfsg-5~bpo12+12023.12+dfsg-12023.12+dfsg-1~bpo12+12023.12.1+dfsg-12023.12.1+dfsg-1~bpo12+12023.12.1+dfsg-22023.12.1+dfsg-2~bpo12+12024.05+dfsg-12024.05.2+dfsg-12024.05.2+dfsg-22024.05.2+dfsg-2~bpo12+12024.12+dfsg-12024.12+dfsg-22024.12+dfsg-2~bpo12+12024.12.1+dfsg-12024.12.1+dfsg-1~bpo12+12024.12.1+dfsg-22024.12.1+dfsg-32024.12.1+dfsg-3~bpo12+12025.05+dfsg-12025.05+dfsg-22025.05+dfsg-2~bpo13+12025.05+dfsg-32025.05+dfsg-3~bpo13+12025.12+dfsg-12025.12+dfsg-102025.12+dfsg-10~bpo13+12025.12+dfsg-10~bpo13+22025.12+dfsg-22025.12+dfsg-2~bpo13+12025.12+dfsg-32025.12+dfsg-42025.12+dfsg-52025.12+dfsg-62025.12+dfsg-72025.12+dfsg-7~bpo13+12025.12+dfsg-82025.12+dfsg-92026.05+dfsg-1 |
None known |
swupdateDebian:13 |
All versions, plus listed versions 2024.12.1+dfsg-32024.12.1+dfsg-3+deb13u12024.12.1+dfsg-3+deb13u22025.05+dfsg-12025.05+dfsg-2 Show 27 moreShow less2025.05+dfsg-2~bpo13+12025.05+dfsg-32025.05+dfsg-3~bpo13+12025.12+dfsg-12025.12+dfsg-102025.12+dfsg-10~bpo13+12025.12+dfsg-10~bpo13+22025.12+dfsg-22025.12+dfsg-2~bpo13+12025.12+dfsg-32025.12+dfsg-42025.12+dfsg-52025.12+dfsg-62025.12+dfsg-72025.12+dfsg-7~bpo13+12025.12+dfsg-82025.12+dfsg-92026.05+dfsg-12026.05+dfsg-22026.05+dfsg-32026.05+dfsg-3~bpo13+12026.05+dfsg-42026.05.1+dfsg-12026.05.1+dfsg-1~bpo13+12026.05.1+git20261001+dfsg-12026.05.1+git20261001+dfsg-22026.05.1+git20261001+dfsg-2~bpo13+1 |
None known |
swupdateDebian:14 |
before 2025.12+dfsg-10, plus listed versions 2024.12.1+dfsg-32025.05+dfsg-12025.05+dfsg-22025.05+dfsg-2~bpo13+12025.05+dfsg-3 Show 14 moreShow less2025.05+dfsg-3~bpo13+12025.12+dfsg-12025.12+dfsg-10~bpo13+12025.12+dfsg-10~bpo13+22025.12+dfsg-22025.12+dfsg-2~bpo13+12025.12+dfsg-32025.12+dfsg-42025.12+dfsg-52025.12+dfsg-62025.12+dfsg-72025.12+dfsg-7~bpo13+12025.12+dfsg-82025.12+dfsg-9 |
2025.12+dfsg-10 |
Mongoose_jllJulia |
before 7.21.0+0 | 7.21.0+0 |
swupdateUbuntu:22.04:LTS |
All versions, plus listed versions 2020.11-22021.04-1.12021.04-22021.04-2build12021.11-1 |
None known |
swupdateUbuntu:24.04:LTS |
All versions, plus listed versions 2023.05+dfsg-32023.05+dfsg-42023.05+dfsg-4build12023.05+dfsg-52023.12+dfsg-12023.12.1+dfsg-1ubuntu12023.12.1+dfsg-1ubuntu42023.12.1+dfsg-1ubuntu5 |
None known |
swupdateUbuntu:25.10 |
All versions, plus listed versions 2024.12.1+dfsg-1build22024.12.1+dfsg-22024.12.1+dfsg-32025.05+dfsg-2ubuntu1 |
None known |
swupdateUbuntu:26.10 |
All versions, plus listed versions 2025.12+dfsg-4ubuntu12026.05+dfsg-3ubuntu22026.05+dfsg-4ubuntu12026.05.1+dfsg-1ubuntu12026.05.1+git20261001+dfsg-1ubuntu1 |
None known |
swupdateUbuntu:26.04:LTS |
All versions, plus listed versions 2025.05+dfsg-2ubuntu12025.05+dfsg-3ubuntu12025.12+dfsg-1ubuntu12025.12+dfsg-2ubuntu12025.12+dfsg-3ubuntu12025.12+dfsg-4ubuntu1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-5246 is a medium vulnerability (CVSS 6.3) in Automattic Mongoose, published April 2, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.65%, the 51st percentile. Fixed in swupdate 2025.12+dfsg-10.
References
Left out here: 9 versions. The JSON record has them.