CVE-2026-104851

HIGHPre-NVD 8.88.8
EchelonGraph scoreHIGH confidence

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

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-10-05. A secondary CVSS source baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — Patch released this weekElevated

Also known asEUVD-2026-91720 (ENISA EUVD) · GHSA-27vj-qcqg-25rc (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.

fsspec is a specification and Python implementation framework for filesystem interfaces. From 0.9.0 until 2026.6.0, fsspec.implementations.reference.ReferenceFileSystem evaluates fields from Kerchunk reference JSON documents through unrestricted jinja2.Template(...).render(...) calls in _process_references1._render_jinja, _process_templates, and _process_gen in fsspec/implementations/reference.py. A document supplied inline or fetched from an attacker-controlled URL can provide template expressions that execute Python code when the reference filesystem is opened, including through consumers such as xarray, before referenced data is read. The _process_gen path is reached whenever a document includes a gen array, while the other paths depend on template-related options and values. This issue is fixed in version 2026.6.0.

CVSS v3
8.8
EG Score
8.8HIGHhigh confidence
EG Risk
56
EG Risk 56/100

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.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (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: 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
41st
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.GitHub Security Advisory CVSS
EG Likelihood
0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-31). 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, Track* at medium and Attend at high mission impact.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, 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, Track* at medium and Attend at high mission impact.

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 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.

The score's inputs: 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 2, 2026

Last Modified

October 5, 2026

Advisory Details (5)

Auto-updated Oct 2, 2026
Patch available. Sources: github_pr, github_commit, github.
GitHub commit

commit a1c16ab3f07f (fsspec/filesystem_spec)

Fix landed in fsspec/filesystem_spec commit a1c16ab3f07f — awaiting tagged release

https://github.com/fsspec/filesystem_spec/commit/a1c16ab3f07f354aa371c38f7b1b07ea7fd4c5c8
GitHub commit

commit 86438783f93b (fsspec/filesystem_spec)

Fix landed in fsspec/filesystem_spec commit 86438783f93b — awaiting tagged release

https://github.com/fsspec/filesystem_spec/commit/86438783f93b1398ef245b92f0e6063b445b611c
GitHub pull request

Small safety improvements

Fix merged in fsspec/filesystem_spec PR #2039 on 2026-05-15 — awaiting tagged release

https://github.com/fsspec/filesystem_spec/pull/2039
GitHub pull request

Honour simple_templates everywhere in referenceFS

Fix merged in fsspec/filesystem_spec PR #2029 on 2026-05-15 — awaiting tagged release

https://github.com/fsspec/filesystem_spec/pull/2029
GitHub advisoryMentions a patch (unverified)

Server-Side Template Injection in ReferenceFileSystem leads to Remote Code Execution · Advisory · fsspec/filesystem_spec · GitHub

https://github.com/fsspec/filesystem_spec/security/advisories/GHSA-27vj-qcqg-25rc

Patch Availability(15)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatrhoai/odh-openvino-model-server-rhel9:17926839542026-10-29redhat
redhatrhelai3/disk-image-cuda-rhel9:17927017962026-10-26redhat
redhatrhelai3/bootc-rocm-rhel9:17926129212026-10-26redhat
redhatrhoai/odh-feature-server-rhel9:17921485232026-10-21redhat
redhatansible-automation-platform-26/lightspeed-chatbot-rhel9:17919787982026-10-21redhat
redhatansible-automation-platform-27/lightspeed-chatbot-rhel9:17923859712026-10-21redhat
redhatrhoai/odh-workbench-jupyter-trustyai-cpu-py312-rhel9:17918163162026-10-21redhat
redhatrhoai/odh-workbench-jupyter-trustyai-cpu-py312-rhel9:17918295302026-10-19redhat
redhatrhaii/model-opt-cuda-rhel9:17918571102026-10-14redhat
redhatrhaii/vllm-spyre-rhel9:17918585922026-10-14redhat
redhatrhaii/vllm-cpu-rhel9:17918573012026-10-14redhat
redhatrhaii/vllm-cuda-rhel9:17918571832026-10-14redhat
redhatrhaii/vllm-rocm-rhel9:17918567252026-10-14redhat
redhatrhaii/vllm-spyre-rhel9:17918183572026-10-13redhat
pipfsspec @ 2026.6.0 (fixes >= 0.9.0, < 2026.6.0)—ghsa

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(4 across 4 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
fsspec2022.11.0-1 ... 2026.9.0-1 (23 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
fsspec2025.12.0-1 ... 2026.9.0-1 (7 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
fsspec2025.12.0-1 ... 2026.9.0-1 (7 versions)
  • every version on: no fix on record
—
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
fsspec0.9.0 ... 2026.4.0 (58 versions)
  • 0.9.0 up to 2026.6.0: fixed in 2026.6.0
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 54× 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% · 41st percentile
  2. 2026-11-01 08:00 UTCGHSA enrichmentGHSA-27vj-qcqg-25rc · GitHub severity HIGH · GitHub CVSS 8.8
  3. 2026-11-01 08:00 UTCEG score recompute
  4. 2026-10-31 20:16 UTCEG score recompute
  5. 2026-10-31 20:16 UTCVendor advisory
  6. 2026-10-31 16:31 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  7. 2026-10-30 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  8. 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  9. 2026-10-28 16:31 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  10. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  11. 2026-10-26 16:30 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  12. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  13. 2026-10-25 14:55 UTCEG score recompute
  14. 2026-10-24 19:57 UTCEG score recompute
  15. 2026-10-24 19:57 UTCVendor advisory
  16. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  17. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  18. 2026-10-22 16:33 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  19. 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  20. 2026-10-20 16:31 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  21. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  22. 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  23. 2026-10-18 05:09 UTCEG score recompute
  24. 2026-10-17 19:39 UTCEG score recompute
  25. 2026-10-17 19:39 UTCVendor advisory
Show 32 more
  1. 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  2. 2026-10-16 16:40 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  3. 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  4. 2026-10-14 16:31 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  5. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  6. 2026-10-12 16:40 UTCEG score recompute
  7. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  8. 2026-10-11 20:15 UTCEG score recompute
  9. 2026-10-11 18:27 UTCEG score recompute
  10. 2026-10-11 15:01 UTCEG score recompute
  11. 2026-10-11 13:47 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  12. 2026-10-10 22:14 UTCEG score recompute
  13. 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  14. 2026-10-09 21:46 UTCEG score recompute
  15. 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  16. 2026-10-08 21:27 UTCEG score recompute
  17. 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  18. 2026-10-08 09:15 UTCEG score recompute
  19. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  20. 2026-10-06 20:48 UTCEG score recompute
  21. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  22. 2026-10-05 20:26 UTCEG score recompute
  23. 2026-10-05 20:13 UTCEG score recompute
  24. 2026-10-05 19:45 UTCEG score recompute
  25. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  26. 2026-10-05 07:37 UTCEG score recompute
  27. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  28. 2026-10-03 19:08 UTCEG score recompute
  29. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  30. 2026-10-02 17:29 UTCEG score recompute
  31. 2026-10-02 16:45 UTCEG score recomputeFirst assessed: 8.8 HIGH
  32. 2026-10-02 16:45 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-104851?
CVE-2026-104851 is a high-severity vulnerability; its CVE record was published on October 2, 2026. fsspec is a specification and Python implementation framework for filesystem interfaces. From 0.9.0 until 2026.6.0, fsspec.implementations.reference.ReferenceFileSystem evaluates fields from Kerchunk reference JSON documents through unrestricted jinja2.Template(...).render(...) calls in…
When was the CVE record for CVE-2026-104851 published?
The CVE record for CVE-2026-104851 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 5, 2026; the record at its source may have been updated since.
Is CVE-2026-104851 actively exploited?
CVE-2026-104851 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (41st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-104851?
CVE-2026-104851 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-2026-104851?
A fix for CVE-2026-104851 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-104851 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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