Evidence used
- No CISA KEV confirmation is currently recorded.
- The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
- EPSS is 0.61% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2025
CVE-2025-21599High confidence
Junos OS Evolved: Receipt of specifically malformed IPv6 packets causes kernel memory exhaustion leading to Denial of Service
Juniper Networks · Junos OS Evolved
8.7HighCVSS 4.0
Within 7 days
Patch availableHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:High, unchanged from published severity.unchanged
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 Juniper Networks Junos OS Evolved 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.
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Patch available01
What, why and how
A Missing Release of Memory after Effective Lifetime vulnerability in the Juniper Tunnel Driver (jtd) of Juniper Networks Junos OS Evolved allows an unauthenticated network-based attacker to cause Denial of Service. Receipt of specifically malformed IPv6 packets, destined to the device, causes kernel memory to not be freed, resulting in memory exhaustion leading to a system crash and Denial of Service (DoS). Continuous receipt and processing of these packets will continue to exhaust kernel memory, creating a sustained Denial of Service (DoS) condition. This issue only affects systems configured with IPv6. This issue affects Junos OS Evolved: * from 22.4-EVO before 22.4R3-S5-EVO, * from 23.2-EVO before 23.2R2-S2-EVO, * from 23.4-EVO before 23.4R2-S2-EVO, * from 24.2-EVO before 24.2R1-S2-EVO, 24.2R2-EVO. This issue does not affect Juniper Networks Junos OS Evolved versions prior to 22.4R1-EVO.
What
A Missing Release of Memory after Effective Lifetime vulnerability in the Juniper Tunnel Driver (jtd) of Juniper Networks Junos OS Evolved allows an unauthenticated network-based attacker to cause Denial of Service. Receipt of specifically malformed IPv6 packets, destined to the device, causes kernel memory to not be freed, resulting in memory exhaustion leading to a system crash and Denial of Service (DoS). Continuous receipt and processing of these packets will continue to exhaust kernel memory, creating a sustained Denial of Service (DoS) condition. This issue only affects systems configured with IPv6. This issue affects Junos OS Evolved: * from 22.4-EVO before 22.4R3-S5-EVO, * from 23.2-EVO before 23.2R2-S2-EVO, * from 23.4-EVO before 23.4R2-S2-EVO, * from 24.2-EVO before 24.2R1-S2-EVO, 24.2R2-EVO. This issue does not affect Juniper Networks Junos OS Evolved versions prior to 22.4R1-EVO.
Why
The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.
What
A Missing Release of Memory after Effective Lifetime vulnerability in the Juniper Tunnel Driver (jtd) of Juniper Networks Junos OS Evolved allows an unauthenticated network-based attacker to cause Denial of Service. Receipt of specifically malformed IPv6 packets, destined to the device, causes kernel memory to not be freed, resulting in memory exhaustion leading to a system crash and Denial of Service (DoS). Continuous receipt and processing of these packets will continue to exhaust kernel memory, creating a sustained Denial of Service (DoS) condition. This issue only affects systems configured with IPv6. This issue affects Junos OS Evolved: * from 22.4-EVO before 22.4R3-S5-EVO, * from 23.2-EVO before 23.2R2-S2-EVO, * from 23.4-EVO before 23.4R2-S2-EVO, * from 24.2-EVO before 24.2R1-S2-EVO, 24.2R2-EVO. This issue does not affect Juniper Networks Junos OS Evolved versions prior to 22.4R1-EVO.
Why
The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 → Missing Release of Memory after Effective Lifetime → disrupt the affected service
- Attack surface
- Network
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Not a CVSS 4.0 base metric
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-401 ↗
CWE-401: Missing Release of Memory after Effective Lifetime. The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:LCommon Vulnerability Scoring System 4.0: 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.ATNoneAttack requirements: No additional deployment or execution condition is required.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.VCNoneVulnerable-system confidentiality: No direct loss is represented by this metric.VINoneVulnerable-system integrity: No direct loss is represented by this metric.VAHighVulnerable-system availability: A successful attack can cause a major loss.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SALowSubsequent-system availability: A successful attack can cause a limited loss.- 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.
03
Patch and workaround
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. - Patch available
- Fixed
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- 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 9 Jan 2025 · Last source change 9 Jan 2025, 19:22 UTC · CWE-401 · Missing Release of Memory after Effective Lifetime
CVE recordCVE.org · 5.1
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2025-2565
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
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.