A signature verification vulnerability was discovered in the update installation functionality due to inconsistent validation of the update bundle contents. An attacker with administrative privileges can remotely supply a crafted update bundle that passes signature verification but runs an unsigned script when the bundle is installed. The script runs with root privileges, allowing the attacker to read or modify sensitive data, change the appliance configuration, or shut down the appliance.
CVE-2026-33923
HIGHPre-NVD 7.27.2Trending — 5 sources updated this week
EchelonGraph scoreHIGH confidence
“—” beside the score: it is equal to the CVSS score beside it.
Score 7.2 from GitHub Security Advisory (severity: HIGH) published 2026-10-29. A secondary CVSS source baseline 7.2; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: GitHub Security Advisory, a secondary CVSS source
Also known asEUVD-2026-112723 (ENISA EUVD) · GHSA-9v7w-2fr3-g7q8 (GitHub Security Advisories)Source: ENISA EUVD
7.2EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 7.2Exploit: None knownExposed services: Not assessed
Upgrade to v26.4.0 or later (from the CVE record's solution, Nozomi Networks Inc.) — apply it.
- CVSS v3
- 7.2
- EG Score
- 7.2HIGHhigh confidence
- EG Risk
- 32EG Risk 32/100
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)Severity72% × 45%Impact severity (EG Severity): CVSS 7.2 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation0% × 40%No KEV listing, EG-KEV tier or EPSS when EchelonGraph scored this CVE.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).Exploitation none (CISA Vulnrichment) · Automatable no (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: Upgrade to v26.4.0 or later (from the CVE record's solution, Nozomi Networks Inc.). Apply it within your standard update timelines. - EPSS PROB
- 0.2%
- EPSS %ILE
- 13th
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (7.2): severity, escalated by confirmed exploitation. This CVE's 7.2 is its impact severity (EG Severity), not escalated.
- EG Severity
- 7.2 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS. FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
Upgrade to v26.4.0 or later (from the CVE record's solution, Nozomi Networks Inc.). Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (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)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable no (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
Published
October 29, 2026
Last Modified
October 29, 2026
Advisory Details (1)
Auto-updated Oct 29, 2026Fix named in the CVE record's solution (Nozomi Networks Inc.).
Web page
NN-2026:21-01 - Update bundle signature bypass in Guardian/CMC before 26.4.0 - CVE-2026-33923 | Product Security Incident Response Portal
https://security.nozominetworks.com/NN-2026:21-01Vendor Advisories for CVE-2026-33923(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 10× in last 7d / 10× 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.
- 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.2% · 13th percentile
- 2026-10-29 16:08 UTCGHSA enrichmentGHSA-9v7w-2fr3-g7q8 · GitHub severity HIGH · GitHub CVSS 7.2
- 2026-10-29 13:26 UTCEG score recompute
- 2026-10-29 13:26 UTCGHSA enrichmentGHSA-9v7w-2fr3-g7q8 · GitHub severity HIGH · GitHub CVSS 7.2
- 2026-10-29 12:49 UTCEG score recompute
- 2026-10-29 12:49 UTCGHSA enrichmentGHSA-9v7w-2fr3-g7q8 · GitHub severity HIGH · GitHub CVSS 7.2
- 2026-10-29 11:26 UTCEG score recompute
- 2026-10-29 11:02 UTCENISA EUVD ID recordedEUVD-2026-112723 · Source: ENISA EUVD
- 2026-10-29 10:55 UTCEG score recomputeFirst assessed: 7.2 HIGH
- 2026-10-29 10:53 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-33923?
CVE-2026-33923 is a high-severity vulnerability; its CVE record was published on October 29, 2026. A signature verification vulnerability was discovered in the update installation functionality due to inconsistent validation of the update bundle contents. An attacker with administrative privileges can remotely supply a crafted update bundle that passes signature verification but runs an unsigned…
When was CVE-2026-33923 made public?
CVE-2026-33923 was made public on October 29, 2026: that is the date its CVE record's CNA, Nozomi Networks Inc., gives for when the vulnerability was made public. The CVE record itself was published on October 29, 2026. EchelonGraph's copy of the record carries a last-modified date of October 29, 2026; the record at its source may have been updated since.
Is CVE-2026-33923 actively exploited?
CVE-2026-33923 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (13th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-33923?
CVE-2026-33923 has a CVSS base score of 7.2 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-33923?
The CVE record's solution for CVE-2026-33923, written by its CNA Nozomi Networks Inc., names the fix: "Upgrade to v26.4.0 or later." The vendor advisories EchelonGraph has for CVE-2026-33923 are linked in the Vendor Advisories panel on this page.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-33923
Is Your Infrastructure Affected by CVE-2026-33923?
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