CVE catalog
CVE-2026-104851
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
- Severity
- High · CVSS 8.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Published
- Updated
- Source
- [NVD] · [CVE record]
- EPSS
- 0.47% · Oct 25, 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 _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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | fsspec | sid | 2026.9.0-1 | fixed |
| Debian | fsspec | forky | 2026.9.0-1 | fixed |
| Debian | fsspec | trixie | 2025.3.2-1 | vulnerable |
| Debian | fsspec | bookworm | 2022.11.0-1 | vulnerable |
| PyPI | fsspec | Not reported | 0.9.0 | vulnerable |
| PyPI | fsspec | Not reported | 2021.10.0 | vulnerable |
| PyPI | fsspec | Not reported | 2021.10.1 | vulnerable |
| PyPI | fsspec | Not reported | 2021.11.0 | vulnerable |
| PyPI | fsspec | Not reported | 2021.11.1 | vulnerable |
| PyPI | fsspec | Not reported | 2021.4.0 | vulnerable |
| PyPI | fsspec | Not reported | 2021.5.0 | vulnerable |
| PyPI | fsspec | Not reported | 2021.6.0 | vulnerable |
| PyPI | fsspec | Not reported | 2021.6.1 | vulnerable |
| PyPI | fsspec | Not reported | 2021.7.0 | vulnerable |
| PyPI | fsspec | Not reported | 2021.8.1 | vulnerable |
| PyPI | fsspec | Not reported | 2021.9.0 | vulnerable |
| PyPI | fsspec | Not reported | 2022.1.0 | vulnerable |
| PyPI | fsspec | Not reported | 2022.10.0 | vulnerable |
| PyPI | fsspec | Not reported | 2022.11.0 | vulnerable |
| PyPI | fsspec | Not reported | 2022.2.0 | vulnerable |
| PyPI | fsspec | Not reported | 2022.3.0 | vulnerable |
| PyPI | fsspec | Not reported | 2022.5.0 | vulnerable |
| PyPI | fsspec | Not reported | 2022.7.0 | vulnerable |
| PyPI | fsspec | Not reported | 2022.7.1 | vulnerable |
| PyPI | fsspec | Not reported | 2022.8.0 | vulnerable |
| PyPI | fsspec | Not reported | 2022.8.1 | vulnerable |
| PyPI | fsspec | Not reported | 2022.8.2 | vulnerable |
| PyPI | fsspec | Not reported | 2023.1.0 | vulnerable |
| PyPI | fsspec | Not reported | 2023.10.0 | vulnerable |
| PyPI | fsspec | Not reported | 2023.12.0 | vulnerable |
| PyPI | fsspec | Not reported | 2023.12.1 | vulnerable |
| PyPI | fsspec | Not reported | 2023.12.2 | vulnerable |
| PyPI | fsspec | Not reported | 2023.3.0 | vulnerable |
| PyPI | fsspec | Not reported | 2023.4.0 | vulnerable |
| PyPI | fsspec | Not reported | 2023.5.0 | vulnerable |
| PyPI | fsspec | Not reported | 2023.6.0 | vulnerable |
| PyPI | fsspec | Not reported | 2023.9.0 | vulnerable |
| PyPI | fsspec | Not reported | 2023.9.1 | vulnerable |
| PyPI | fsspec | Not reported | 2023.9.2 | vulnerable |
| PyPI | fsspec | Not reported | 2024.10.0 | vulnerable |
| PyPI | fsspec | Not reported | 2024.12.0 | vulnerable |
| PyPI | fsspec | Not reported | 2024.2.0 | vulnerable |
| PyPI | fsspec | Not reported | 2024.3.0 | vulnerable |
| PyPI | fsspec | Not reported | 2024.3.1 | vulnerable |
| PyPI | fsspec | Not reported | 2024.5.0 | vulnerable |
| PyPI | fsspec | Not reported | 2024.6.0 | vulnerable |
| PyPI | fsspec | Not reported | 2024.6.1 | vulnerable |
| PyPI | fsspec | Not reported | 2024.9.0 | vulnerable |
| PyPI | fsspec | Not reported | 2025.10.0 | vulnerable |
| PyPI | fsspec | Not reported | 2025.12.0 | vulnerable |
| PyPI | fsspec | Not reported | 2025.2.0 | vulnerable |
| PyPI | fsspec | Not reported | 2025.3.0 | vulnerable |
| PyPI | fsspec | Not reported | 2025.3.1 | vulnerable |
| PyPI | fsspec | Not reported | 2025.3.2 | vulnerable |
| PyPI | fsspec | Not reported | 2025.5.0 | vulnerable |
| PyPI | fsspec | Not reported | 2025.5.1 | vulnerable |
| PyPI | fsspec | Not reported | 2025.7.0 | vulnerable |
| PyPI | fsspec | Not reported | 2025.9.0 | vulnerable |
| PyPI | fsspec | Not reported | 2026.1.0 | vulnerable |
| PyPI | fsspec | Not reported | 2026.2.0 | vulnerable |
| PyPI | fsspec | Not reported | 2026.3.0 | vulnerable |
| PyPI | fsspec | Not reported | 2026.4.0 | vulnerable |
| PyPI | fsspec | Not reported | 2026.6.0 | fixed |
| PyPI | fsspec | Not reported | 0.9.0 | vulnerable |
| PyPI | fsspec | Not reported | 2021.10.0 | vulnerable |
| PyPI | fsspec | Not reported | 2021.10.1 | vulnerable |
| PyPI | fsspec | Not reported | 2021.11.0 | vulnerable |
| PyPI | fsspec | Not reported | 2021.11.1 | vulnerable |
| PyPI | fsspec | Not reported | 2021.4.0 | vulnerable |
| PyPI | fsspec | Not reported | 2021.5.0 | vulnerable |
| PyPI | fsspec | Not reported | 2021.6.0 | vulnerable |
| PyPI | fsspec | Not reported | 2021.6.1 | vulnerable |
| PyPI | fsspec | Not reported | 2021.7.0 | vulnerable |
| PyPI | fsspec | Not reported | 2021.8.1 | vulnerable |
| PyPI | fsspec | Not reported | 2021.9.0 | vulnerable |
| PyPI | fsspec | Not reported | 2022.1.0 | vulnerable |
| PyPI | fsspec | Not reported | 2022.10.0 | vulnerable |
| PyPI | fsspec | Not reported | 2022.11.0 | vulnerable |
| PyPI | fsspec | Not reported | 2022.2.0 | vulnerable |
| PyPI | fsspec | Not reported | 2022.3.0 | vulnerable |
| PyPI | fsspec | Not reported | 2022.5.0 | vulnerable |
| PyPI | fsspec | Not reported | 2022.7.0 | vulnerable |
| PyPI | fsspec | Not reported | 2022.7.1 | vulnerable |
| PyPI | fsspec | Not reported | 2022.8.0 | vulnerable |
| PyPI | fsspec | Not reported | 2022.8.1 | vulnerable |
| PyPI | fsspec | Not reported | 2022.8.2 | vulnerable |
| PyPI | fsspec | Not reported | 2023.1.0 | vulnerable |
| PyPI | fsspec | Not reported | 2023.10.0 | vulnerable |
| PyPI | fsspec | Not reported | 2023.12.0 | vulnerable |
| PyPI | fsspec | Not reported | 2023.12.1 | vulnerable |
| PyPI | fsspec | Not reported | 2023.12.2 | vulnerable |
| PyPI | fsspec | Not reported | 2023.3.0 | vulnerable |
| PyPI | fsspec | Not reported | 2023.4.0 | vulnerable |
| PyPI | fsspec | Not reported | 2023.5.0 | vulnerable |
| PyPI | fsspec | Not reported | 2023.6.0 | vulnerable |
| PyPI | fsspec | Not reported | 2023.9.0 | vulnerable |
| PyPI | fsspec | Not reported | 2023.9.1 | vulnerable |
| PyPI | fsspec | Not reported | 2023.9.2 | vulnerable |
| PyPI | fsspec | Not reported | 2024.10.0 | vulnerable |
| PyPI | fsspec | Not reported | 2024.12.0 | vulnerable |
| PyPI | fsspec | Not reported | 2024.2.0 | vulnerable |
| PyPI | fsspec | Not reported | 2024.3.0 | vulnerable |
| PyPI | fsspec | Not reported | 2024.3.1 | vulnerable |
| PyPI | fsspec | Not reported | 2024.5.0 | vulnerable |
| PyPI | fsspec | Not reported | 2024.6.0 | vulnerable |
| PyPI | fsspec | Not reported | 2024.6.1 | vulnerable |
| PyPI | fsspec | Not reported | 2024.9.0 | vulnerable |
| PyPI | fsspec | Not reported | 2025.10.0 | vulnerable |
| PyPI | fsspec | Not reported | 2025.12.0 | vulnerable |
| PyPI | fsspec | Not reported | 2025.2.0 | vulnerable |
| PyPI | fsspec | Not reported | 2025.3.0 | vulnerable |
| PyPI | fsspec | Not reported | 2025.3.1 | vulnerable |
| PyPI | fsspec | Not reported | 2025.3.2 | vulnerable |
| PyPI | fsspec | Not reported | 2025.5.0 | vulnerable |
| PyPI | fsspec | Not reported | 2025.5.1 | vulnerable |
| PyPI | fsspec | Not reported | 2025.7.0 | vulnerable |
| PyPI | fsspec | Not reported | 2025.9.0 | vulnerable |
| PyPI | fsspec | Not reported | 2026.1.0 | vulnerable |
| PyPI | fsspec | Not reported | 2026.2.0 | vulnerable |
| PyPI | fsspec | Not reported | 2026.3.0 | vulnerable |
| PyPI | fsspec | Not reported | 2026.4.0 | vulnerable |
| PyPI | fsspec | Not reported | 2026.6.0 | fixed |
| Opensuse | python-fsspec | leap 16.0 | 2024.3.1-bp160.2.1 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | fsspec | source | sid | 2026.9.0-1 | not yet assigned | Not reported | [1149800] |
| Debian | fsspec | source | forky | 2026.9.0-1 | not yet assigned | Not reported | [1149800] |
| Debian | fsspec | source | trixie | (unfixed) | not yet assigned | Not reported | [1149800] |
| Debian | fsspec | source | bookworm | (unfixed) | not yet assigned | Not reported | [1149800] |
| PyPI | fsspec | PyPI | Not reported | 2026.6.0 | Not reported | PYSEC-2026-4217 | Not reported |
| PyPI | fsspec | PyPI | Not reported | 2026.6.0 | Not reported | GHSA-27VJ-QCQG-25RC | Not reported |
| Opensuse | python-fsspec | rpm | leap 16.0 | 2024.3.1-bp160.2.1 | Not reported | OPENSUSE-SU-2026:22028-1 | Not reported |
Notes
[trixie] fsspec: Minor issue [bookworm] fsspec: Minor issue
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [python3-fsspec]Affected
Source package: [fsspec]
Details (2)
2022.11.0-1· all · bookwormAffected
nvd · fsspec · debian · bookworm; nvd · fsspec · debian · 12
2022.11.0-1· all · bookwormAffected
nvd · fsspec · debian · bookworm; nvd · fsspec · debian · 12
- [python-fsspec-doc]Affected
Source package: [fsspec]
Details (2)
2022.11.0-1· all · bookwormAffected
nvd · fsspec · debian · bookworm; nvd · fsspec · debian · 12
2022.11.0-1· all · bookwormAffected
nvd · fsspec · debian · bookworm; nvd · fsspec · debian · 12
[Debian 13 (Trixie)]
- [python3-fsspec]Affected
Source package: [fsspec]
Details (2)
2025.3.2-1· all · trixieAffected
nvd · fsspec · debian · 13
2025.3.2-1· all · trixieAffected
nvd · fsspec · debian · 13
- [python-fsspec-doc]Affected
Source package: [fsspec]
Details (2)
2025.3.2-1· all · trixieAffected
nvd · fsspec · debian · 13
2025.3.2-1· all · trixieAffected
nvd · fsspec · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/opensuse-su-2026_22028-1.json]
- [https://github.com/advisories/GHSA-27vj-qcqg-25rc]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-104851]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-104851]
- [https://osv.dev/vulnerability/PYSEC-2026-4217]
- [https://osv.dev/vulnerability/openSUSE-SU-2026:22028-1]
- [https://security-tracker.debian.org/tracker/CVE-2026-104851]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-104851.json]
[Debian Security Tracker] · [FIRST EPSS] · [GitHub Advisory Database] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]