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NVD / CVE Program· CNA juniper

CVE-2023-0026: 2023-06: Out-of-Cycle Security Bulletin: Junos OS and Junos OS Evolved: A BGP session will flap upon receipt of a specific, optional transitive attribute

Noroxi assessment

Priority: Monitor (action score 30/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.64% (FIRST EPSS); higher than 50.9% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • According to the record, no fixed version is available yet.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

An Improper Input Validation vulnerability in the Routing Protocol Daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS). When a BGP update message is received over an established BGP session, and that message contains a specific, optional transitive attribute, this session will be torn down with an update message error. This issue cannot propagate beyond an affected system as the processing error occurs as soon as the update is received. This issue is exploitable remotely as the respective attribute can propagate through unaffected systems and intermediate AS (if any). Continuous receipt of a BGP update containing this attribute will create a sustained Denial of Service (DoS) condition. Some customers have experienced these BGP session flaps which prompted Juniper SIRT to release this advisory out of cycle before fixed releases are widely available as there is an effective workaround. This issue affects: Juniper Networks Junos OS 15.1R1 and later versions prior to 20.4R3-S8; 21.1 version 21.1R1 and later versions prior to 21.2R3-S6; 21.3 versions prior to 21.3R3-S5; 21.4 versions prior to 21.4R3-S4; 22.1 versions prior to 22.1R3-S4; 22.2 versions prior to 22.2R3-S2; 22.3 versions prior to 22.3R2-S2, 22.3R3-S1; 22.4 versions prior to 22.4R2-S1, 22.4R3; 23.1 versions prior to 23.1R1-S1, 23.1R2. Juniper Networks Junos OS Evolved All versions prior to 20.4R3-S8-EVO; 21.1 version 21.1R1-EVO and later versions prior to 21.2R3-S6-EVO; 21.3 versions prior to 21.3R3-S5-EVO; 21.4 versions prior to 21.4R3-S4-EVO; 22.1 versions prior to 22.1R3-S4-EVO; 22.2 versions prior to 22.2R3-S2-EVO; 22.3 versions prior to 22.3R2-S2-EVO, 22.3R3-S1-EVO; 22.4 versions prior to 22.4R2-S1-EVO, 22.4R3-EVO; 23.1 versions prior to 23.1R1-S1-EVO, 23.1R2-EVO.

HighCVSS 7.5 · v3.1—No exploit No fix recorded
Published
Jun 21, 2023
Updated
Jun 17, 2026
EPSS
0.6% · 50th percentile

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.6%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · juniper
7.5
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2023-0026

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
juniperjunos
juniperjunos os evolved

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • juniper junos15.1 and later · before 20.4
  • juniper junos20.4
  • juniper junos21.1
  • juniper junos21.2
  • juniper junos21.3
  • juniper junos21.4
  • juniper junos22.1
  • juniper junos22.2
  • juniper junos22.3
  • juniper junos22.4
  • juniper junos os evolvedbefore 20.4
  • juniper junos os evolved20.4
  • juniper junos os evolved21.1
  • juniper junos os evolved21.2
  • juniper junos os evolved21.3
  • juniper junos os evolved21.4
  • juniper junos os evolved22.1
  • juniper junos os evolved22.2
  • juniper junos os evolved22.3
  • juniper junos os evolved22.4

Versions reported by the vendor

Affected version ranges reported by the assigning authority (juniper). Independent of NVD's CPE analysis and usually ahead of it.

  • Juniper Networks Junos OS

    • unspecified and later · before 15.1R1not affected
    • unspecified and later · before 20.4R3-S8affected
    • 21.1 and later · before 21.1*affected
    • 21.2 and later · before 21.2R3-S6affected
    • 21.3 and later · before 21.3R3-S5affected
    • 21.4 and later · before 21.4R3-S4affected
    • 22.1 and later · before 22.1R3-S4affected
    • 22.2 and later · before 22.3R2-S2, 22.3R3-S1affected
    • 22.3 and later · before 22.2R3-S2affected
    • 22.4 and later · before 22.4R2-S1, 22.4R3affected

  • Juniper Networks Junos OS Evolved

    • unspecified and later · before 20.4R3-S8-EVOaffected
    • 21.1R1-EVO and later · before 21.1*affected
    • 21.2 and later · before 21.2R3-S6-EVOaffected
    • 21.3 and later · before 21.3R3-S5-EVOaffected
    • 21.4 and later · before 21.4R3-S4-EVOaffected
    • 22.1 and later · before 22.1R3-S4-EVOaffected
    • 22.2 and later · before 22.2R3-S2-EVOaffected
    • 22.3 and later · before 22.3R2-S2-EVO, 22.3R3-S1-EVOaffected
    • 22.4 and later · before 22.4R2-S1-EVO, 22.4R3-EVOaffected
    • 23.1 and later · before 23.1R1-S1-EVO, 23.1R2-EVOaffected

Same product

juniper: all records

Other highest-scoring records for the same primary product.

  • CVE-2023-36845Junos OS: EX and SRX Series: A PHP vulnerability in J-Web allows an unauthenticated to control an important environment variableKEV
    98Now
  • CVE-2023-36846Junos OS: SRX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload arbitrary filesKEV
    79This week
  • CVE-2023-36844Junos OS: EX Series: A PHP vulnerability in J-Web allows an unauthenticated attacker to control important environment variablesKEV
    78This week

Published before and after this one in the same product

  • ← EarlierCVE-2023-28982Apr 17, 2023 · Junos OS and Junos OS Evolved: In a BGP rib sharding scenario when a route is frequently updated an rpd memory leak will occur
    30Monitor
  • ← EarlierCVE-2023-28984Apr 17, 2023 · Junos OS: QFX Series: The PFE may crash when a lot of MAC addresses are being learned and aged
    21Monitor
  • Later →CVE-2023-36831Jul 14, 2023 · Junos OS: SRX Series: jbuf memory leak when SSL Proxy and UTM Web-Filtering is applied
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-20 · Improper Input Validation

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records