mwiede jsch up to 2.28.5 KnownHosts.java getRevokedKeys known_hosts improper check for certificate revocation

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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3.4$0-$5k1.02

Summaryinfo

A vulnerability labeled as problematic has been found in mwiede jsch up to 2.28.5. Affected by this vulnerability is the function getRevokedKeys of the file src/main/java/com/jcraft/jsch/KnownHosts.java. Executing a manipulation of the argument known_hosts can lead to improper check for certificate revocation. This vulnerability appears as CVE-2026-86231. The attack may be performed from remote. In addition, an exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability has been found in mwiede jsch up to 2.28.5 and classified as problematic. This vulnerability affects the function getRevokedKeys of the file src/main/java/com/jcraft/jsch/KnownHosts.java. The manipulation of the argument known_hosts with an unknown input leads to a improper check for certificate revocation vulnerability. The CWE definition for the vulnerability is CWE-299. The product does not check or incorrectly checks the revocation status of a certificate, which may cause it to use a certificate that has been compromised. As an impact it is known to affect integrity.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-86231. The exploitation appears to be difficult. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details and also a public exploit are known. The MITRE ATT&CK project declares the attack technique as T1557.003.

It is possible to download the exploit at github.com. It is declared as proof-of-concept.

Upgrading to version 2.28.6 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 194a2f76a5c0f1c3f778565be3fd66bcafc42d23 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-72179). Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.7
VulDB Meta Temp Score: 3.4

VulDB Base Score: 3.7
VulDB Temp Score: 3.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Improper check for certificate revocation
CWE: CWE-299 / CWE-298 / CWE-295
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Access: Public
Status: Proof-of-Concept
Download: 🔒
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: jsch 2.28.6
Patch: 194a2f76a5c0f1c3f778565be3fd66bcafc42d23

Timelineinfo

09/06/2026 Advisory disclosed
09/06/2026 +0 days VulDB entry created
09/07/2026 +1 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: 1091
Status: Confirmed
Confirmation: 🔒

CVE: CVE-2026-86231 (🔒)
GCVE (CVE): GCVE-0-2026-86231
GCVE (VulDB): GCVE-100-399388
EUVD: 🔒
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 09/06/2026 10:09
Updated: 09/07/2026 03:05
Changes: 09/06/2026 10:09 (63), 09/07/2026 03:05 (1)
Complete: 🔍
Submitter: Yu Bao from PayPal Cyber Security Team
Cache ID: 216::103

Submitinfo

Accepted

  • Submit #898485: mwiede jsch 2.28.4 Cert Revocation Type String Bypass (by Yu Bao from PayPal Cyber Security Team)

Once again VulDB remains the best source for vulnerability data.

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