Cesanta Mongoose TLS 1.3 mongoose.c mg_tls_recv_cert heap-based overflow

MITRE NVD CVE.ORG Print: PDF PDF

Summary

CVECVE-2026-5244
StatePUBLISHED
AssignerVulDB
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-04-02 08:16:28 UTC
Updated2026-04-03 16:10:52 UTC
DescriptionA vulnerability has been found in Cesanta Mongoose up to 7.20. This affects the function mg_tls_recv_cert of the file mongoose.c of the component TLS 1.3 Handler. Such manipulation of the argument pubkey leads to heap-based buffer overflow. The attack may be launched remotely. The exploit has been disclosed to the public and may be used. Upgrading to version 7.21 mitigates this issue. The name of the patch is 0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1. It is advisable to upgrade the affected component. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.

Risk And Classification

Primary CVSS: v4.0 6.9 MEDIUM from [email protected]

CVSS:4.0/AV:N/AC:L/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

EPSS: 0.000580000 probability, percentile 0.182250000 (date 2026-04-02)

Problem Types: CWE-119 | CWE-122 | CWE-122 Heap-based Buffer Overflow | CWE-119 Memory Corruption

VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary6.9MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/C...
4.0CNADECLARED6.9MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
3.1[email protected]Primary7.3HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
3.1CNADECLARED7.3HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C
3.0CNADECLARED7.3HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C
2.0[email protected]Secondary7.5AV:N/AC:L/Au:N/C:P/I:P/A:P
2.0CNADECLARED7.5AV:N/AC:L/Au:N/C:P/I:P/A:P/E:POC/RL:OF/RC:C

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Confidentiality
Low
Integrity
Low
Availability
Low
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:N/AC:L/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 v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

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

CVSS v3.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Cesanta Mongoose affected 7.0 Not specified
CNA Cesanta Mongoose affected 7.1 Not specified
CNA Cesanta Mongoose affected 7.2 Not specified
CNA Cesanta Mongoose affected 7.3 Not specified
CNA Cesanta Mongoose affected 7.4 Not specified
CNA Cesanta Mongoose affected 7.5 Not specified
CNA Cesanta Mongoose affected 7.6 Not specified
CNA Cesanta Mongoose affected 7.7 Not specified
CNA Cesanta Mongoose affected 7.8 Not specified
CNA Cesanta Mongoose affected 7.9 Not specified
CNA Cesanta Mongoose affected 7.10 Not specified
CNA Cesanta Mongoose affected 7.11 Not specified
CNA Cesanta Mongoose affected 7.12 Not specified
CNA Cesanta Mongoose affected 7.13 Not specified
CNA Cesanta Mongoose affected 7.14 Not specified
CNA Cesanta Mongoose affected 7.15 Not specified
CNA Cesanta Mongoose affected 7.16 Not specified
CNA Cesanta Mongoose affected 7.17 Not specified
CNA Cesanta Mongoose affected 7.18 Not specified
CNA Cesanta Mongoose affected 7.19 Not specified
CNA Cesanta Mongoose affected 7.20 Not specified
CNA Cesanta Mongoose unaffected 7.21 Not specified

References

ReferenceSourceLinkTags
vuldb.com/submit/770063 [email protected] vuldb.com
vuldb.com/vuln/354825/cti [email protected] vuldb.com
vuldb.com/vuln/354825 [email protected] vuldb.com
github.com/cesanta/mongoose/releases/tag/7.21 [email protected] github.com
github.com/cesanta/mongoose [email protected] github.com
github.com/cesanta/mongoose/commit/0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1 [email protected] github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: the_evilsocket (VulDB User) (en)

CNA: VulDB (en)

Additional Advisory Data

SourceTimeEvent
CNA2026-04-02T00:00:00.000ZAdvisory disclosed
CNA2026-04-02T02:00:00.000ZVulDB entry created
CNA2026-04-02T09:48:19.000ZVulDB entry last update
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