Deserialization in Stanford Stanza
CVE-2026-54499
Stanza is a Stanford NLP Python library for tokenization, sentence segmentation, NER, and parsing of many human languages. Prior to 1.12.2, Stanza model loaders such as stanza.models.common.pretrain.Pretrain.load() attempt torch.load(..., weights_only=True) but fall back to torch.load(..., weights_only=False) on attacker-controllable pickle.UnpicklingError, allowing a malicious .pt pretrain or model file to execute arbitrary pickle code when a Stanza NLP pipeline loads it. This issue is fixed in version 1.12.2.
Vulnerability class: Insecure Deserialization
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.005 (42.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 42.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- Stanford Stanza
- Stanfordnlp Stanza — versions < 1.12.2
Weakness classification (CWE)
References
- github.com/stanfordnlp/stanza/security/advisories/GHSA-v5jw-96jm-7h2c (Exploit, Vendor Advisory)
- github.com/stanfordnlp/stanza/pull/1587 (Patch, Issue Tracking)
- github.com/stanfordnlp/stanza/commit/b745008c68c9e50ccb5acd537cb6f2453f8b7ad4 (Patch)
- github.com/stanfordnlp/stanza/releases/tag/v1.12.2 (Release Notes)
Frequently asked questions
- What is CVE-2026-54499?
- CVE-2026-54499 is a high-severity vulnerability in Stanford Stanza, classified under Deserialization of Untrusted Data. CVSS score: 7.5/10. Published 2026-07-08.
- How severe is CVE-2026-54499?
- High severity. CVSS v3 base score is 7.5 out of 10.