Deserialization in Flairnlp Flair
CVE-2026-76843
The official Flair wheels for 0.15.0 and 0.15.1 still contain flair/models/clustering.py, whose ClusteringModel.load static method returns pickle.loads(joblib.load(str(model_file))) and so executes arbitrary Python while loading a model file. Loading a model supplied by an attacker therefore runs that attacker's code with the privileges of the loading process. This is the same sink and the same file as CVE-2024-10073, which records 0.15.0 as the fixed version on the basis that clustering support was dropped in that release; the module was removed from the documented API but remains present in the distributed artifact and reachable by importing flair.models.clustering directly, so the earlier record's fixed version does not hold for the shipped package.
Vulnerability class: Insecure Deserialization
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.004 (29.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 29.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.004 · change: +0.002
Affected products
Weakness classification (CWE)
References
- github.com/flairNLP/flair (product)
- github.com/flairNLP/flair/blob/v0.15.1/flair/models/clustering.py (technical-description)
- pypi.org/project/flair/0.15.1/ (product)
- www.vulncheck.com/advisories/flair-and-deserialization-of-untrusted-data-via-cl… (third-party-advisory)
- github.com/flairNLP/flair/blob/v0.14.0/flair/models/clustering.py (technical-description)
Frequently asked questions
- What is CVE-2026-76843?
- CVE-2026-76843 is a high-severity vulnerability in Flairnlp Flair, classified under Deserialization of Untrusted Data. CVSS score: 7.8/10. Published 2026-08-24.
- How severe is CVE-2026-76843?
- High severity. CVSS v3 base score is 7.8 out of 10.