CVE-2026-103958

HIGHPre-NVD 7.67.6
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 7.6 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit probability: 0.4% (28th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from the CNA's CVSS
Sources: the CNA's CVSS, EPSS

Also known asEUVD-2026-91773 (ENISA EUVD)Source: ENISA EUVD

7.6EG
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: 0.4%CVSS: 7.6Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Server-side request forgery in the tool server and remote agent connection handling in Loom for AWS before 1.7.0 might allow an authenticated remote user to obtain the credentials of the application's own container role and to read responses from arbitrary internal network locations, via a crafted connection address supplied when registering, updating or testing a tool server or remote agent.

To remediate this issue, users should upgrade to version 1.7.0 or later.

CVSS v3
7.6
EG Score
7.6HIGHmedium confidence
EG Risk
34
EG Risk 34/100

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)
Severity76% × 45%
Impact severity (EG Severity): CVSS 7.6 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (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.
EPSS PROB
0.4%
EPSS %ILE
28th
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 (7.6): severity, escalated by confirmed exploitation. This CVE's 7.6 is its impact severity (EG Severity), not escalated.

EG Severity
7.6 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.the CNA's CVSS · CVSS v3.0 or v3.1
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-30). 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 every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade 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 every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (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)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (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 2, 2026

Last Modified

October 9, 2026

Advisory Details (2)

Auto-updated Oct 2, 2026
Patch available. Sources: github_release.
Web page

CVE-2026-103956, CVE-2026-103957, and CVE-2026-103958 - Issues in Loom for AWS

https://aws.amazon.com/security/security-bulletins/2026-124-aws/
GitHub release Patch Available

v1.7.0

Patch available: awslabs/loom v1.7.0

https://github.com/awslabs/loom/releases/tag/v1.7.0

Vendor Advisories for CVE-2026-103958(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 8× in last 7d / 48× 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. 2026-11-03 16:45 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  2. 2026-11-02 16:43 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  3. 2026-11-01 16:33 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  4. 2026-10-31 16:31 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  5. 2026-10-30 20:51 UTCEG score recompute
  6. 2026-10-30 16:33 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  7. 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  8. 2026-10-28 16:31 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  9. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  10. 2026-10-26 16:30 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  11. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  12. 2026-10-25 14:56 UTCEG score recompute
  13. 2026-10-24 16:31 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  14. 2026-10-24 08:17 UTCEG score recompute
  15. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  16. 2026-10-22 16:33 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  17. 2026-10-21 16:31 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  18. 2026-10-20 16:31 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  19. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  20. 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  21. 2026-10-18 05:09 UTCEG score recompute
  22. 2026-10-17 19:41 UTCEG score recompute
  23. 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  24. 2026-10-16 16:40 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  25. 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.3% · 24th percentile
Show 29 more
  1. 2026-10-14 16:31 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  2. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  3. 2026-10-12 16:40 UTCEG score recompute
  4. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  5. 2026-10-11 20:15 UTCEG score recompute
  6. 2026-10-11 18:28 UTCEG score recompute
  7. 2026-10-11 15:01 UTCEG score recompute
  8. 2026-10-11 13:47 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  9. 2026-10-11 03:59 UTCEG score recompute
  10. 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  11. 2026-10-10 04:26 UTCEG score recompute
  12. 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  13. 2026-10-09 16:40 UTCEG score recompute
  14. 2026-10-08 17:52 UTCEG score recompute
  15. 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  16. 2026-10-08 05:50 UTCEG score recompute
  17. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  18. 2026-10-06 18:33 UTCEG score recompute
  19. 2026-10-06 18:03 UTCEG score recompute
  20. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  21. 2026-10-05 18:59 UTCEG score recompute
  22. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  23. 2026-10-05 07:14 UTCEG score recompute
  24. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  25. 2026-10-03 19:54 UTCEG score recompute
  26. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  27. 2026-10-02 19:20 UTCEG score recompute
  28. 2026-10-02 19:10 UTCEG score recomputeFirst assessed: 7.6 HIGH
  29. 2026-10-02 19:10 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-103958?
CVE-2026-103958 is a high-severity vulnerability; its CVE record was published on October 2, 2026. Server-side request forgery in the tool server and remote agent connection handling in Loom for AWS before 1.7.0 might allow an authenticated remote user to obtain the credentials of the application's own container role and to read responses from arbitrary internal network locations, via a crafted…
When was the CVE record for CVE-2026-103958 published?
The CVE record for CVE-2026-103958 was published on October 2, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 9, 2026; the record at its source may have been updated since.
Is CVE-2026-103958 actively exploited?
CVE-2026-103958 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (28th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-103958?
CVE-2026-103958 has a CVSS base score of 7.6 (the CNA's own assessment, by amzn; NVD's own analysis pending).
How do I remediate CVE-2026-103958?
A fix for CVE-2026-103958 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-103958 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-103958

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