Security readout for executives and security teams
Plain-English summary
Junos Space TLS/SSL can allow static key cipher suites. These weaken confidentiality because they lack Perfect Forward Secrecy, so captured encrypted traffic may have weaker long-term protection. Juniper states all Junos Space versions before 24.1R5 are affected.
Executive priority
Prioritize remediation for Junos Space systems handling sensitive management traffic or exposed beyond tightly controlled networks. This is a confidentiality issue, not a reported outage or takeover issue, but the CVSS score is High.
Technical view
CVE-2026-21907 is CWE-327 in the Junos Space TLS/SSL server. CVSS v4.0 is 8.2 High. The issue permits ssl-static-key-ciphers, reducing confidentiality for on-path communications. No integrity or availability impact is described in the provided sources.
Likely exposure
Organizations running Juniper Networks Junos Space before 24.1R5, especially where its TLS/SSL service is reachable by users, administrators, or networks carrying sensitive management traffic.
Exploitation context
The provided sources do not report active exploitation, and KEV is false. Risk centers on an on-path attacker observing or influencing protected communications when static key ciphers are available or negotiated.
Researcher notes
Key facts: Junos Space before 24.1R5; CWE-327; CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:L/SI:N/SA:N/AU:Y/RE:M/U:Green. The affected version data in the bundle is sparse, so rely on the vendor advisory for exact release guidance.
Mitigation direction
- Upgrade Junos Space to 24.1R5 or a later vendor-supported release.
- Review Juniper advisory JSA106006 for any additional vendor instructions.
- Restrict access to Junos Space management interfaces to trusted networks.
- If vendor-supported, configure TLS to avoid static key cipher suites.
Validation and detection
- Inventory all Junos Space instances and record installed versions.
- Flag any Junos Space version earlier than 24.1R5 as affected.
- Use approved TLS assessment tooling to check whether static key ciphers are offered.
- After remediation, verify only vendor-approved cipher suites remain enabled.
- Monitor Juniper advisory JSA106006 for updates or revised guidance.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-327: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-21907 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.2 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:L/SI:N/SA:N/AU:Y/RE:M/U:Green
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:L/SI:N/SA:N/AU:Y/RE:M/U:Green——Primary CVE scoreVulnerability scoring details
Base CVSS 4.0 score
8.2HighVector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:L/SI:N/SA:N/AU:Y/RE:M/U:Green
Source materials
- CVE List V5 sourceCVE List V5
- https://supportportal.juniper.net/JSA106006CVE reference · vendor-advisory
- https://kb.juniper.net/JSA106006CVE reference · vendor-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Use of a Broken or Risky Cryptographic Algorithm
Use of a Broken or Risky Cryptographic Algorithm represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.