CVE-2026-103090

HIGHPre-NVD 8.88.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

This high-severity CVE scores 8.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5% (43rd percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Trending — 3 sources updated this weekElevated

Also known asEUVD-2026-107668 (ENISA EUVD) · GHSA-xhg2-hv24-f4rp (GitHub Security Advisories)Source: ENISA EUVD

8.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 8.8Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

Missing Authentication for Critical Function (CWE-306) and Insufficiently Protected Credentials (CWE-522) in the control plane enrollment status handler (HandleEnrollStatus at GET /enroll/status in internal/controlplane/server.go) in Google OSS Agent Mesh (SAM) versions 0.1.0-alpha.1 through 0.1.0-alpha.8 allow an unauthenticated remote attacker to retrieve an approved bootstrap-enrolled peer's signed Biscuit identity token by supplying a peer_id obtainable from the unauthenticated GET /info endpoint. A related flaw in POST /enroll allowed any bootstrap-token holder to re-fetch another peer's credential. An attacker can replay the disclosed Biscuit token as a bearer credential on /policies to read mesh authorization policies and on /routers/lease to overwrite advertised router multiaddrs. Users should upgrade to version 0.1.0-alpha.9 or later, which requires cryptographic proof of possession of the enrollment private key on credential-releasing endpoints, enforces rate limiting, and validates router lease addresses.

CVSS v3
8.8
EG Score
8.8HIGHmedium confidence
EG Risk
71
EG Risk 71/100

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)
Severity88% × 45%
Impact severity (EG Severity): CVSS 8.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (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: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.5%
EPSS %ILE
43rd
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 (8.8): severity, escalated by confirmed exploitation. This CVE's 8.8 is its impact severity (EG Severity), not escalated.

EG Severity
8.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.5% 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; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days 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)Track at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (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; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (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 21, 2026

Last Modified

October 30, 2026

Advisory Details (2)

Auto-updated Oct 21, 2026
🔬 Proof of concept available. Patch available. Sources: github_release, github.
GitHub release Patch Available

v0.1.0-alpha.9

Patch available: google/sam v0.1.0-alpha.9

https://github.com/google/sam/releases/tag/v0.1.0-alpha.9
GitHub advisoryMentions a patch (unverified)🟡 PoC Available

Unauthenticated GET /enroll/status returns an approved peer's Biscuit, which the same control plane then accepts as a bearer credential · Advisory · google/agentmesh · GitHub

https://github.com/google/sam/security/advisories/GHSA-hp3x-79wr-rx66

Vendor Advisories for CVE-2026-103090(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 15× in last 7d / 24× 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.

  1. 2026-11-01 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  2. 2026-10-31 16:31 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  3. 2026-10-30 19:34 UTCEG score recompute
  4. 2026-10-30 19:34 UTCGHSA enrichmentGHSA-xhg2-hv24-f4rp · GitHub severity HIGH
  5. 2026-10-30 18:26 UTCEG score recompute
  6. 2026-10-30 18:26 UTCGHSA enrichmentGHSA-xhg2-hv24-f4rp · GitHub severity HIGH
  7. 2026-10-30 17:35 UTCEG score recompute
  8. 2026-10-30 17:35 UTCGHSA enrichmentGHSA-xhg2-hv24-f4rp · GitHub severity HIGH
  9. 2026-10-30 16:33 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  10. 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  11. 2026-10-28 16:31 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  12. 2026-10-27 20:36 UTCEG score recompute
  13. 2026-10-27 20:36 UTCGHSA enrichmentGHSA-xhg2-hv24-f4rp · GitHub severity HIGH
  14. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  15. 2026-10-26 16:30 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  16. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  17. 2026-10-25 14:56 UTCEG score recompute
  18. 2026-10-24 16:31 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  19. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  20. 2026-10-22 16:33 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  21. 2026-10-22 16:26 UTCGHSA enrichmentGHSA-xhg2-hv24-f4rp · GitHub severity HIGH
  22. 2026-10-21 23:27 UTCEG score recompute
  23. 2026-10-21 22:31 UTCEG score recomputeFirst assessed: 8.8 HIGH
  24. 2026-10-21 22:30 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-103090?
CVE-2026-103090 is a high-severity vulnerability; its CVE record was published on October 21, 2026. Missing Authentication for Critical Function (CWE-306) and Insufficiently Protected Credentials (CWE-522) in the control plane enrollment status handler (HandleEnrollStatus at GET /enroll/status in internal/controlplane/server.go) in Google OSS Agent Mesh (SAM) versions 0.1.0-alpha.1 through…
When was CVE-2026-103090 made public?
CVE-2026-103090 was made public on September 6, 2026: that is the date its CVE record's CNA, Google LLC, gives for when the vulnerability was made public. The CVE record itself was published on October 21, 2026. EchelonGraph's copy of the record carries a last-modified date of October 30, 2026; the record at its source may have been updated since.
Is CVE-2026-103090 actively exploited?
CVE-2026-103090 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (43rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-103090?
CVE-2026-103090 has a CVSS base score of 8.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-103090?
A fix for CVE-2026-103090 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-103090 are linked in the Vendor Advisories panel on this page.

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