Published severityHigh→Operational priority:High, unchanged from published severity.unchanged
Evidence used
No CISA KEV confirmation is currently recorded.
EPSS is 0.44% for the current model date.
Compensating controls
Validate the affected product branch and deploy the verified fixed release.
Restrict the affected network interface to trusted sources where business-safe.
Monitor vendor guidance and exploitation sources for a material change.
Verification
Confirm that the asset runs Jenkins Project Jenkins and falls inside the recorded affected range.
Verify the installed build against the product-specific fixed version after deployment.
Validate exposure, authentication requirements and compensating controls in the actual environment.
Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Direct vendor intelligence
Authoritative vendor CSAF and VEX advisories
Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.
1 current
CVE-2026-84652 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityjenkins: Jenkins: Authentication bypass via session cookie non-rotation
1 known affected
The vendor explicitly identifies these products as affected by this CVE.
jenkins.src as a component of OpenShift Developer Tools and Services
Summary
A flaw was found in Jenkins. When a user authenticates using the "remember me" cookie, Jenkins fails to rotate the session identifier. This oversight allows a remote attacker, who can serve content on the same site as Jenkins, to set a known session cookie in a victim's browser. Consequently, once the victim authenticates, the attacker can use the known session cookie to gain unauthorized access to Jenkins as that user, leading to an authentication bypass.
Remediation
It is recommended that existing users of Red Hat OpenShift Developer Tools - OpenShift Jenkins 4-12 upgrade to the latest.
Optional official sources
National CERT insights ?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.
Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.
Official European source
ENISA European Vulnerability Database
Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.
1 current
ENISA EUVD identifier
EUVD-2026-70118
No EUVD known-exploited evidence
In Jenkins 2.579 and earlier, LTS 2.568.2 and earlier, Jenkins does not rotate the session when a user is authenticated via the "remember me" cookie, allowing attackers able to serve content on the same site as Jenkins to set a known session cookie in the victim's browser, which after the victim authenticates via the "remember me" cookie, grants the attacker access to Jenkins as that user.
EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
7.3 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Patch available
01
What, why and how
In Jenkins 2.579 and earlier, LTS 2.568.2 and earlier, Jenkins does not rotate the session when a user is authenticated via the "remember me" cookie, allowing attackers able to serve content on the same site as Jenkins to set a known session cookie in the victim's browser, which after the victim authenticates via the "remember me" cookie, grants the attacker access to Jenkins as that user.
What
In Jenkins 2.579 and earlier, LTS 2.568.2 and earlier, Jenkins does not rotate the session when a user is authenticated via the "remember me" cookie, allowing attackers able to serve content on the same site as Jenkins to set a known session cookie in the victim's browser, which after the victim authenticates via the "remember me" cookie, grants the attacker access to Jenkins as that user.
Why
Authenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
In Jenkins 2.579 and earlier, LTS 2.568.2 and earlier, Jenkins does not rotate the session when a user is authenticated via the "remember me" cookie, allowing attackers able to serve content on the same site as Jenkins to set a known session cookie in the victim's browser, which after the victim authenticates via the "remember me" cookie, grants the attacker access to Jenkins as that user.
Why
Authenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation ?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No confirmed evidence
No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material ?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.None recorded
No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
Likely attack path
a network path → Session Fixation → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
Low: a basic authenticated account is required
User interaction
Required interaction required
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness ?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-384: Session Fixation. Authenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions.
CVSS vector ?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UIRequiredUser interaction: Another user must perform an action for exploitation to succeed.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.ANoneAvailability impact: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkCWE-384
A
Official authority intelligence
Only matched European and national findings are included. Language selectors and unavailable sources are omitted.
ENISA EUVD · EUVD-2026-70118Official EUVD mapping
In Jenkins 2.579 and earlier, LTS 2.568.2 and earlier, Jenkins does not rotate the session when a user is authenticated via the "remember me" cookie, allowing attackers able to serve content on the same site as Jenkins to set a known session cookie in the victim's browser, which after the victim authenticates via the "remember me" cookie, grants the attacker access to Jenkins as that user.
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Jenkins und verschiedenen Plugins ausnutzen, um Daten offenzulegen oder zu manipulieren, Cross-Site Scripting (XSS) durchzuführen, beliebigen Code auszuführen oder die Sitzung eines anderen Benutzers zu übernehmen.
Official advisory ↗Cyber Security Agency of Singapore · English · CSA-SB-20260909Security Bulletin 9 Sep 2026
The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 9 Sep 2026, published on 9 September 2026. Open the linked bulletin for the product, severity and reference information published in that issue.
Official advisory ↗CSIRT Italia · Italian · rilevate-nuove-vulnerabilita-in-jenkins-3Rilevate nuove vulnerabilità in Jenkins
Aggiornamenti di sicurezza Jenkins sanano molteplici vulnerabilità, di cui 6 con gravità "alta", presenti nel software open source per l'automazione di processi di integrazione e distribuzione continua (CI/CD).
Official advisory ↗JVN iPedia · Japanese · JVNDB-2026-033340Jenkinsにおけるセッションの固定化の脆弱性
Operational remediation based on structured source evidence.
Status ?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
It is recommended that existing users of Red Hat OpenShift Developer Tools - OpenShift Jenkins 4-12 upgrade to the latest.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 2 Sept 2026 · Last source change 3 Sept 2026, 15:22 UTC · CWE-384 · Session Fixation
CVE recordCVE.org · 5.2
CVSS sourceCISA ADP
EPSS source ?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.FIRST · tracked since 2026-09-03
European sourceENISA EUVD · EUVD-2026-70118
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCISA ADP
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Affected versionsThe structured affected or fixed version information changed.
Before
jenkins.src as a component of OpenShift Developer Tools and Services
After
jenkins.src as a component of OpenShift Developer Tools and Services · Fixed: registry.redhat.io/ocp-tools-4/jenkins-rhel8@sha256:96e5820b8b83bde089b7449a089d66be83f42cedf407ee0803ef26a545544fde_amd64 as a component of OpenShift Developer Tools and Services 4.12; registry.redhat.io/ocp-tools-4/jenkins-rhel8@sha256:06cc882c326c72292a6fcb50de0aca29f53441dcacabe5bf789ede3387a7c4b9_amd64 as a component of OpenShift Developer Tools and Services 4.13; registry.redhat.io/ocp-tools-4/jenkins-rhel8@sha256:238668e54ad9af2e06b4dd44d228d237a012d3c4ca63db8d67558cd5e5963c48_ppc64le as a component of OpenShift Developer Tools and Services 4.14; registry.redhat.io/ocp-tools-4/jenkins-rhel8@sha256:9b2f4a67ed2e0fb3336ede98aa08ff729349f8937540f0179678a108e043f6e5_arm64 as a component of OpenShift Developer Tools and Services 4.14; registry.redhat.io/ocp-tools-4/jenkins-rhel8@sha256:c03355915f59dd67f6465e52586330f519ac97b9013ddc278867555ced2d9fac_amd64 as a component of OpenShift Developer Tools and Services 4.14; registry.redhat.io/ocp-tools-4/jenkins-rhel8@sha256:ca36e015c03fdb7fc6db4a853543b54e13089209b29edca03d0ced3ead13ccd7_s390x as a component of OpenShift Developer Tools and Services 4.14; registry.redhat.io/ocp-tools-4/jenkins-rhel8@sha256:36ac037350e6d22a050538e4537efb8c4f2273f0bc34cf698e386e77aa3c4b9e_ppc64le as a component of OpenShift Developer Tools and Services 4.15; registry.redhat.io/ocp-tools-4/jenkins-rhel8@sha256:69b329adeb51d7cfa805dd9431c53965e2dca0b12481312182307aa6e6b0f74f_amd64 as a component of OpenShift Developer Tools and Services 4.15; registry.redhat.io/ocp-tools-4/jenkins-rhel8@sha256:838f50f79bd5f179dd96aad91d1a494e2430550888a2ce58c2a48a0a2d1ae2c4_arm64 as a component of OpenShift Developer Tools and Services 4.15; registry.redhat.io/ocp-tools-4/jenkins-rhel8@sha256:8baac2caa310a35bb92dadf7d035e0aea83d793e0dc1796106ef5b55c2cb60a3_s390x as a component of OpenShift Developer Tools and Services 4.15; registry.redhat.io/ocp-tools-4/jenkins-rhel9@sha256:1d29650794888ecc4e455b2e9588a1068cd602ee9079759599611c8dc1e2442f_arm64 as a component of OpenShift Developer Tools and Services 4.16; registry.redhat.io/ocp-tools-4/jenkins-rhel9@sha256:6df696cfde5dd9e20e654da5f1c68c0e9784545830702943cb48d5510109a6ad_amd64 as a component of OpenShift Developer Tools and Services 4.16; registry.redhat.io/ocp-tools-4/jenkins-rhel9@sha256:89f5d0c3c54bbb3dd907a77693a127f62b5d415e4e1920a940b0cd57fca67e9e_s390x as a component of OpenShift Developer Tools and Services 4.16; registry.redhat.io/ocp-tools-4/jenkins-rhel9@sha256:a77e3be5f3fffeee0cb7cb3fba2f3f8529d279757e52aab6fb0ba35bb4f9b1fd_ppc64le as a component of OpenShift Developer Tools and Services 4.16; registry.redhat.io/ocp-tools-4/jenkins-rhel9@sha256:27c9b8b8253e74632c8f3437c3a9a6b1c4ff1f8aa1b278a354d9747269ec9249_arm64 as a component of OpenShift Developer Tools and Services 4.17; registry.redhat.io/ocp-tools-4/jenkins-rhel9@sha256:384dab79ba9ac7e7b3ddfdc1733f75c578d89df108e844e3e6167df1b40d0908_s390x as a component of OpenShift Developer Tools and Services 4.17; registry.redhat.io/ocp-tools-4/jenkins-rhel9@sha256:68ea3deee00db002a5857214810732450a613de1daf28c678cd1f0a9288b508d_amd64 as a component of OpenShift Developer Tools and Services 4.17; registry.redhat.io/ocp-tools-4/jenkins-rhel9@sha256:e01fbb27610e869f69ae56bfe41f92ac8ec7144b4ccfc15877a8212198e8b721_ppc64le as a component of OpenShift Developer Tools and Services 4.17; registry.redhat.io/ocp-tools-4/jenkins-rhel9@sha256:44cb8767b56b3b59944600ec9b14e760a82ae7b652071a4a14e58b0269372823_arm64 as a component of OpenShift Developer Tools and Services 4.18; registry.redhat.io/ocp-tools-4/jenkins-rhel9@sha256:65d4c128c0a2fb3d11d4045f9f7540867cb6d080421ec62b1cd4ecceb70264e9_s390x as a component of OpenShift Developer Tools and Services 4.18; registry.redhat.io/ocp-tools-4/jenkins-rhel9@sha256:c02cbeaf85b1feaa1669180a01870674914b0f99a31815931c1dcfc972556799_ppc64le as a component of OpenShift Developer Tools and Services 4.18; registry.redhat.io/ocp-tools-4/jenkins-rhel9@sha256:cff801b41ce61c942e5f561c2271c99cc30e8395547d8328c8a5743561a3afab_amd64 as a component of OpenShift Developer Tools and Services 4.18; registry.redhat.io/ocp-tools-4/jenkins-rhel9@sha256:1ad906acf8a1ea05a5c45c54b28bf2329daeee0eb7e0556a3de2fa3453446b62_s390x as a component of OpenShift Developer Tools and Services 4.19; registry.redhat.io/ocp-tools-4/jenkins-rhel9@sha256:37a9b0d0b81f98a5f4c5858672fb341325f97eeb23a713a9fc400e0a41b73af6_amd64 as a component of OpenShift Developer Tools and Services 4.19; registry.redhat.io/ocp-tools-4/jenkins-rhel9@sha256:9bf61591ae9da1e7ae4cb794333472e636400e17d1227c57bd8cc5b3f5189d0c_ppc64le as a component of OpenShift Developer Tools and Services 4.19; registry.redhat.io/ocp-tools-4/jenkins-rhel9@sha256:d69d03e357eb73621bef90e3144ae5581cc22a355168321bf51a2d5b60b80fb2_arm64 as a component of OpenShift Developer Tools and Services 4.19; registry.redhat.io/ocp-tools-4/jenkins-rhel9@sha256:4e2befa4cba56ae02abb56959b7f4a3a214a249e811664e05bee87fe31b2e2a7_amd64 as a component of OpenShift Developer Tools and Services 4.20; registry.redhat.io/ocp-tools-4/jenkins-rhel9@sha256:544a7a272daef07a62bfe61240c154d28ac7c002e3e64bba6fe79cc949825b68_ppc64le as a component of OpenShift Developer Tools and Services 4.20; registry.redhat.io/ocp-tools-4/jenkins-rhel9@sha256:8e431337a83099fd9e09c259515c766db17c71ee68a8d1cfd5ae3e3b04d2348c_s390x as a component of OpenShift Developer Tools and Services 4.20; registry.redhat.io/ocp-tools-4/jenkins-rhel9@sha256:e6a63d412c8421d7c16933357d361fb0f17eed1a4b7c49e33f871980f4124c21_arm64 as a component of OpenShift Developer Tools and Services 4.20; and 8 more
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.