Unable to find valid certification path while installing any jenkins plugins

Using Jenkins
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1

I use a old jenkins version [2.375.2],Java version is 11.0.19 and Tomcat version is 8.5.99 .In the last 1-year im unable to install/update plugins due to below issue:
sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at java.base/sun.security.provider.certpath.SunCertPathBuilder.build(SunCertPathBuilder.java:146)
at java.base/sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:127)
at java.base/java.security.cert.CertPathBuilder.build(CertPathBuilder.java:297)
at java.base/sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:434)
Caused: sun.security.validator.ValidatorException: PKIX path building failed
at java.base/sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:439)
at java.base/sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:306)
at java.base/sun.security.validator.Validator.validate(Validator.java:264)
at java.base/sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:313)
at java.base/sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:222)
at java.base/sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:129)
at java.base/sun.security.ssl.CertificateMessage$T13CertificateConsumer.checkServerCerts(CertificateMessage.java:1341)
Caused: javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at java.base/sun.security.ssl.Alert.createSSLException(Alert.java:131)
at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:360)
at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:303)
at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:298)
at java.base/sun.security.ssl.CertificateMessage$T13CertificateConsumer.checkServerCerts(CertificateMessage.java:1357)
at java.base/sun.security.ssl.CertificateMessage$T13CertificateConsumer.onConsumeCertificate(CertificateMessage.java:1232)
at java.base/sun.security.ssl.CertificateMessage$T13CertificateConsumer.consume(CertificateMessage.java:1175)
at java.base/sun.security.ssl.SSLHandshake.consume(SSLHandshake.java:392)
at java.base/sun.security.ssl.HandshakeContext.dispatch(HandshakeContext.java:443)
at java.base/sun.security.ssl.HandshakeContext.dispatch(HandshakeContext.java:421)
at java.base/sun.security.ssl.TransportContext.dispatch(TransportContext.java:183)
at java.base/sun.security.ssl.SSLTransport.decode(SSLTransport.java:172)
at java.base/sun.security.ssl.SSLSocketImpl.decode(SSLSocketImpl.java:1507)
at java.base/sun.security.ssl.SSLSocketImpl.readHandshakeRecord(SSLSocketImpl.java:1417)
at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:456)
at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:427)
at java.base/sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:572)
at java.base/sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:201)
at java.base/sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1592)
at java.base/sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1520)
at java.base/sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:250)
at hudson.model.UpdateCenter$UpdateCenterConfiguration.download(UpdateCenter.java:1296)
Caused: java.io.IOException: Failed to load https://updates.jenkins.io/download/plugins/ssh-slaves/2.948.vb_8050d697fec/ssh-slaves.hpi to /proj/igor-ci/jenkinsdata/plugins/ssh-slaves.jpi.tmp
at hudson.model.UpdateCenter$UpdateCenterConfiguration.download(UpdateCenter.java:1307)
Caused: java.io.IOException: Failed to download from https://updates.jenkins.io/download/plugins/ssh-slaves/2.948.vb_8050d697fec/ssh-slaves.hpi
at hudson.model.UpdateCenter$UpdateCenterConfiguration.download(UpdateCenter.java:1341)
at hudson.model.UpdateCenter$DownloadJob._run(UpdateCenter.java:1898)
at hudson.model.UpdateCenter$InstallationJob._run(UpdateCenter.java:2210)
at hudson.model.UpdateCenter$DownloadJob.run(UpdateCenter.java:1872)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at hudson.remoting.AtmostOneThreadExecutor$Worker.run(AtmostOneThreadExecutor.java:121)
at java.base/java.lang.Thread.run(Thread.java:829)

I have the value(http://updates.jenkins-ci.org/update-center.json) in the Update Site URL.

Please help me to direct me where the problem lies.Im clueless here

2

You should not attempt to update plugins when the Jenkins controller is that old. The Jenkins update center only provides plugin version compatibility information for Jenkins controllers released in the last year (roughly). Jenkins 2.375.2 was released two years ago. If you update the plugins, the data from the update center will offer plugins that are not compatible with Jenkins 2.375.2.

Jenkins 2.375.2 has known critical security vulnerabilities. Refer to the Jenkins security advisories for the complete list of vulnerabilities that affect Jenkins 2.375.2.

You should plan an upgrade to the current Jenkins LTS release. When performing that upgrade, you can switch to Java 21, stop using Tomcat, and resolve the critical security vulnerabilities that exist in your current installation.

Since the controller is two years out of date, that likely means the operating system that is running the controller is also out of date. Use this as your justification to replace the operating system with a supported operating system in addition to upgrading Jenkins.