CVE-2023-36851

CRITICALNVD 5.39.0
EchelonGraph scoreHIGH confidence

“▲” beside the score: it is higher than NVD's CVSS score.

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2023-11-13), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 5.3 retained for reference. The 9.0 is the floor for confirmed exploitation, not an impact rating: this CVE's impact severity (EG Severity) is CVSS 5.3 MEDIUM under GitHub Security Advisory CVSS. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: CISA Known Exploited Vulnerabilities catalog, EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 3 sources updated this weekExploited in the wild

Also known asEUVD-2023-40771 (ENISA EUVD) · GHSA-792v-3cgw-26xq (GitHub Security Advisories)Source: ENISA EUVD

9.0EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV) — the reason this is sooner than the SSVC decision on this page at low mission impact
CISA-KEV: ExploitedEPSS PROB: 1.1%CVSS: 5.3Exploit: No code on recordExposed services: Not assessed

The following software releases have been updated to resolve this specific issue: 21.2R3-S8*, 21.4R3-S6*, 22.1R3-S5*, 22.2R3-S3*, 22.3R3-S2*, 22.4R2-S2, 22.4R3*, 23.2R1-S2, 23.2R2*, 23.4R1, and all subsequent releases (from the CVE record's solution, Juniper Networks, Inc.) — apply it.

A Missing Authentication for Critical Function vulnerability in Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause limited impact to the file system integrity.

With a specific request to

webauth_operation.php

that doesn't require authentication, an attacker is able to upload and download arbitrary files via J-Web, leading to a loss of

integrity or confidentiality, which may allow chaining to other vulnerabilities.

This issue affects Juniper Networks Junos OS on SRX Series:

*

21.2 versions prior to 21.2R3-S8; * 21.4

versions prior to

21.4R3-S6; * 22.1

versions prior to

22.1R3-S5; * 22.2

versions prior to

22.2R3-S3; * 22.3

versions prior to

22.3R3-S2; * 22.4 versions prior to 22,4R2-S2, 22.4R3; * 23.2 versions prior to

23.2R1-S2, 23.2R2.

CVSS v3
5.3
EG Score
9.0CRITICALhigh confidence
EG Risk
79
EG Risk 79/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity53% × 45%
Impact severity (EG Severity): CVSS 5.3 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation100% × 40%
Fixed at 100% for a CISA KEV listing: EchelonGraph's rule.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Attend at low mission impact; Act at medium or high.
Exploitation active (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: The following software releases have been updated to resolve this specific issue: 21.2R3-S8*, 21.4R3-S6*, 22.1R3-S5*, 22.2R3-S3*, 22.3R3-S2*, 22.4R2-S2, 22.4R3*, 23.2R1-S2, 23.2R2*, 23.4R1, and all subsequent releases (from the CVE record's solution, Juniper Networks, Inc.). Apply it sooner than your standard update timelines at low mission impact and as soon as possible at medium or high.
EPSS PROB
1.1%
EPSS %ILE
66th
KEV
⚠ Exploited

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (9.0): severity, escalated by confirmed exploitation. This CVE's 9.0 is the CISA KEV floor for confirmed exploitation, not an impact rating: its impact severity (EG Severity) is CVSS 5.3 MEDIUM.

EG Severity
5.3 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
1.1% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-01). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
CISA KEV and EG-KEV Tier 1 (exploited in the wild)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Act at medium mission impactAttend at low mission impact; Act at medium or high.CISA BOD 26-04: 3 days & forensic triage if the affected system is publicly exposed; 3 days & forensic triage if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Attend at low mission impact; Act at medium or high.

The following software releases have been updated to resolve this specific issue: 21.2R3-S8*, 21.4R3-S6*, 22.1R3-S5*, 22.2R3-S3*, 22.3R3-S2*, 22.4R2-S2, 22.4R3*, 23.2R1-S2, 23.2R2*, 23.4R1, and all subsequent releases (from the CVE record's solution, Juniper Networks, Inc.). Apply it sooner than your standard update timelines at low mission impact and as soon as possible at medium or high.

Exploitation active (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)3 days & forensic triage if the affected system is publicly exposed; 3 days & forensic triage if it is not.

The score's inputs: In CISA KEV yes (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

CISA required action“Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.”

Quoted verbatim from CISA's Known Exploited Vulnerabilities catalog. CISA directs it at US federal civilian executive branch agencies under Binding Operational Directive (BOD) 26-04, which replaced BOD 22-01 on 10 June 2026; it is not EchelonGraph's advice. CISA's notes: https://supportportal.juniper.net/s/article/2023-08-Out-of-Cycle-Security-Bulletin-Junos-OS-SRX-Series-and-EX-Series-Multiple-vulnerabilities-in-J-Web-can-be-combined-to-allow-a-preAuth-Remote-Code-Execution?language=en_US · https://nvd.nist.gov/vuln/detail/CVE-2023-36851

Published

September 27, 2023

Last Modified

February 26, 2026

Advisory Details (2)

Auto-updated Oct 27, 2026
⚠️ Actively exploited (CISA KEV, CISA Vulnrichment). Fix named in the CVE record's solution (Juniper Networks, Inc.). Sources: cisa.
CISA🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-36851
Web page

CEC Juniper Community

https://supportportal.juniper.net/JSA72300

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 18× in last 7d / 131× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 1,176 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 1,076 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 16:39 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  2. 2026-11-01 23:44 UTCEG score recompute
  3. 2026-11-01 23:44 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub severity MODERATE · GitHub CVSS 5.3
  4. 2026-10-31 21:31 UTCEG score recompute
  5. 2026-10-31 21:31 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  6. 2026-10-31 16:29 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  7. 2026-10-30 19:19 UTCEG score recompute
  8. 2026-10-30 19:19 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  9. 2026-10-30 16:31 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  10. 2026-10-29 17:06 UTCEG score recompute
  11. 2026-10-29 17:06 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  12. 2026-10-29 16:30 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  13. 2026-10-28 16:29 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  14. 2026-10-28 14:53 UTCEG score recompute
  15. 2026-10-28 14:53 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  16. 2026-10-27 16:29 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  17. 2026-10-27 12:40 UTCEG score recompute
  18. 2026-10-27 12:40 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  19. 2026-10-26 16:28 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  20. 2026-10-26 10:28 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  21. 2026-10-25 17:39 UTCEG score recompute
  22. 2026-10-25 16:29 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  23. 2026-10-25 08:16 UTCEG score recompute
  24. 2026-10-25 08:16 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  25. 2026-10-24 16:29 UTCEPSS rescoreEPSS 1.1% · 66th percentile
Show 75 more
  1. 2026-10-24 06:03 UTCEG score recompute
  2. 2026-10-24 06:03 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  3. 2026-10-23 16:29 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  4. 2026-10-23 03:47 UTCEG score recompute
  5. 2026-10-23 03:47 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  6. 2026-10-22 16:31 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  7. 2026-10-22 01:35 UTCEG score recompute
  8. 2026-10-22 01:35 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  9. 2026-10-21 16:29 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  10. 2026-10-20 23:23 UTCEG score recompute
  11. 2026-10-20 23:22 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  12. 2026-10-20 16:29 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  13. 2026-10-19 21:10 UTCEG score recompute
  14. 2026-10-19 21:10 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  15. 2026-10-19 16:29 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  16. 2026-10-18 18:58 UTCEG score recompute
  17. 2026-10-18 18:58 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  18. 2026-10-18 16:29 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  19. 2026-10-18 07:57 UTCEG score recompute
  20. 2026-10-17 16:44 UTCEG score recompute
  21. 2026-10-17 16:44 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  22. 2026-10-17 16:29 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  23. 2026-10-16 16:35 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  24. 2026-10-16 14:29 UTCEG score recompute
  25. 2026-10-16 14:29 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  26. 2026-10-15 16:29 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  27. 2026-10-15 12:15 UTCEG score recompute
  28. 2026-10-15 12:15 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  29. 2026-10-14 16:29 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  30. 2026-10-14 10:02 UTCEG score recompute
  31. 2026-10-14 10:02 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  32. 2026-10-13 16:30 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  33. 2026-10-13 07:49 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  34. 2026-10-12 18:23 UTCEG score recompute
  35. 2026-10-12 16:30 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  36. 2026-10-12 05:36 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  37. 2026-10-12 01:36 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  38. 2026-10-11 21:37 UTCEG score recompute
  39. 2026-10-11 21:37 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  40. 2026-10-11 17:37 UTCEG score recompute
  41. 2026-10-11 17:37 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  42. 2026-10-11 13:45 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  43. 2026-10-11 13:35 UTCEG score recompute
  44. 2026-10-11 13:35 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  45. 2026-10-11 09:34 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  46. 2026-10-11 05:35 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  47. 2026-10-11 01:35 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  48. 2026-10-10 21:33 UTCEG score recompute
  49. 2026-10-10 21:33 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  50. 2026-10-10 19:57 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  51. 2026-10-10 17:33 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  52. 2026-10-10 13:33 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  53. 2026-10-10 09:33 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  54. 2026-10-10 05:33 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  55. 2026-10-10 01:33 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  56. 2026-10-09 21:33 UTCEG score recompute
  57. 2026-10-09 21:33 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  58. 2026-10-09 20:05 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  59. 2026-10-09 17:33 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  60. 2026-10-09 13:31 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  61. 2026-10-09 09:32 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  62. 2026-10-09 05:32 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  63. 2026-10-09 01:32 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  64. 2026-10-08 21:33 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  65. 2026-10-08 17:33 UTCEG score recompute
  66. 2026-10-08 17:33 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  67. 2026-10-08 17:06 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  68. 2026-10-08 13:33 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  69. 2026-10-08 09:33 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  70. 2026-10-08 05:34 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  71. 2026-10-08 01:35 UTCEG score recompute
  72. 2026-10-08 01:34 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  73. 2026-10-07 23:46 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  74. 2026-10-07 21:35 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3
  75. 2026-10-07 17:35 UTCGHSA enrichmentGHSA-792v-3cgw-26xq · GitHub CVSS 5.3

Frequently asked(6)

What is CVE-2023-36851?
CVE-2023-36851 is a critical-severity vulnerability; its CVE record was published on September 27, 2023. A Missing Authentication for Critical Function vulnerability in Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause limited impact to the file system integrity. With a specific request to webauth_operation.php that doesn't require authentication, an…
When was CVE-2023-36851 made public?
CVE-2023-36851 was made public on September 5, 2023: that is the date its CVE record's CNA, Juniper Networks, Inc., gives for when the vulnerability was made public. The CVE record itself was published on September 27, 2023. EchelonGraph's copy of the record carries a last-modified date of February 26, 2026; the record at its source may have been updated since.
Is CVE-2023-36851 actively exploited?
Yes. CISA added CVE-2023-36851 to the Known Exploited Vulnerabilities catalog on November 13, 2023, affecting Juniper Junos OS. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate attention. The following software releases have been updated to resolve this specific issue: 21.2R3-S8*, 21.4R3-S6*, 22.1R3-S5*, 22.2R3-S3*, 22.3R3-S2*, 22.4R2-S2, 22.4R3*, 23.2R1-S2, 23.2R2*, 23.4R1, and all subsequent releases (from the CVE record's solution, Juniper Networks, Inc.). Apply it.
What is the CVSS score of CVE-2023-36851?
CVE-2023-36851 has a CVSS v3 base score of 5.3 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0 (CRITICAL).
Which products are affected by CVE-2023-36851?
CVE-2023-36851 affects Juniper Junos OS.
How do I remediate CVE-2023-36851?
The CVE record's solution for CVE-2023-36851, written by its CNA Juniper Networks, Inc., names the fix: "The following software releases have been updated to resolve this specific issue: 21.2R3-S8*, 21.4R3-S6*, 22.1R3-S5*, 22.2R3-S3*, 22.3R3-S2*, 22.4R2-S2, 22.4R3*, 23.2R1-S2, 23.2R2*, 23.4R1, and all subsequent releases."

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