mwiede jsch KnownHosts.java getRevokedKeys improper check for certificate revocation

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-86231
StatePUBLISHED
AssignerVulDB
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-06 23:17:39 UTC
Updated2026-09-06 23:17:39 UTC
DescriptionA security flaw has been discovered in mwiede jsch up to 2.28.5. Affected is the function getRevokedKeys of the file src/main/java/com/jcraft/jsch/KnownHosts.java. Performing a manipulation of the argument known_hosts results in improper check for certificate revocation. The attack is possible to be carried out remotely. The attack is considered to have high complexity. The exploitability is told to be difficult. The exploit has been released to the public and may be used for attacks. Upgrading to version 2.28.6 is able to address this issue. The patch is named 194a2f76a5c0f1c3f778565be3fd66bcafc42d23. You should upgrade the affected component.

Risk And Classification

Primary CVSS: v4.0 2.9 LOW from [email protected]

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/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

Problem Types: CWE-298 | CWE-299 | CWE-299 Improper Check for Certificate Revocation | CWE-298 Improper Validation of Certificate Expiration

VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary2.9LOWCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P/C...
4.0CNADECLARED6.3MEDIUMCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P
3.1[email protected]Primary3.7LOWCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
3.1CNADECLARED3.7LOWCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C
3.0CNADECLARED3.7LOWCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C
2.0[email protected]Secondary2.6AV:N/AC:H/Au:N/C:N/I:P/A:N
2.0CNADECLARED2.6AV:N/AC:H/Au:N/C:N/I:P/A:N/E:POC/RL:OF/RC:C

CVSS v4.0 Breakdown

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

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/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
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None

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

CVSS v3.0 Breakdown

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

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Mwiede Jsch affected 2.28.0 Not specified
CNA Mwiede Jsch affected 2.28.1 Not specified
CNA Mwiede Jsch affected 2.28.2 Not specified
CNA Mwiede Jsch affected 2.28.3 Not specified
CNA Mwiede Jsch affected 2.28.4 Not specified
CNA Mwiede Jsch affected 2.28.5 Not specified
CNA Mwiede Jsch unaffected 2.28.6 Not specified

References

ReferenceSourceLinkTags
vuldb.com/vuln/399388 [email protected] vuldb.com
github.com/mwiede/jsch/pull/1098 [email protected] github.com
vuldb.com/submit/898485 [email protected] vuldb.com
github.com/mwiede/jsch [email protected] github.com
github.com/mwiede/jsch/commit/194a2f76a5c0f1c3f778565be3fd66bcafc42d23 [email protected] github.com
github.com/mwiede/jsch/releases/tag/jsch-2.28.6 [email protected] github.com
github.com/mwiede/jsch/issues/1091 [email protected] github.com
vuldb.com/vuln/399388/cti [email protected] vuldb.com
vuldb.com/cve/CVE-2026-86231 [email protected] vuldb.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: Yu Bao from PayPal Cyber Security Team (VulDB User) (en)

Additional Advisory Data

SourceTimeEvent
CNA2026-09-06T00:00:00.000ZAdvisory disclosed
CNA2026-09-06T02:00:00.000ZVulDB entry created
CNA2026-09-06T10:09:53.000ZVulDB entry last update

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