CVSS 3.1
7.8 highCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HCVE-2026-115878
High (7.8). EPSS 0.6% estimated probability of exploitation activity in the next 30 days. Fixed in stanza 1.15.0.
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Stanza is a Stanford NLP Python library for tokenization, sentence segmentation, NER, and parsing of many human languages. From 1.14.0 until 1.15.0, loading an attacker-supplied lemmatizer checkpoint can execute arbitrary code because stanza/models/lemma/trainer.py stores pos_dict as gzip-compressed pickle bytes and Trainer.load passes the decompressed stream to unrestricted pickle.loads. The outer torch.load call uses weights_only=True, but the nested bytes are treated as a primitive and are not inspected by that allowlist. The path is reachable during pipeline construction through a caller-influenced lemma_model_path, before inference begins. This issue is fixed in version 1.15.0.
Severity
- EPSS
- 0.6% estimated probability of exploitation activity in the next 30 days; 49th percentile. Scored 2026-11-04. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: none · Automatable: no · Technical impact: total, assessed 2026-11-03. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWEs
- CWE-94 Improper Control of Generation of Code (Code Injection)
CWE-502 Deserialization of Untrusted Data - Published
- Modified
- Record from
- the NVD, synced
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Explain CVE-2026-115878 for an engineer deciding whether to act. Use https://cve.bz/api/public/cves/CVE-2026-115878?via=ask-ai-copy and https://cve.bz/cve/CVE-2026-115878?via=ask-ai-copy as the source of truth: what is affected and which versions fix it, whether it is in CISA KEV, public exploits, and its EPSS (an internet-wide 30-day estimate of exploitation activity, not a forecast for my systems). If they give no fixed versions, use the CVE record https://cveawg.mitre.org/api/cve/CVE-2026-115878 or the vendor advisory, not third-party mirrors. Tell me how to check whether I am affected and how to verify a fix. Cite the sources and say where they are uncertain.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this CVE's id and public links.
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| stanfordnlp stanza | = 1.14.0 |
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-gh9r-c94j-cmp5 | PyPI | stanza | >=1.14.0 <1.15.0 | 1.15.0 |
Attack patterns (CAPEC)
- CAPEC-586 Object Injection Likelihood: Medium · Severity: High
- CAPEC-35 Leverage Executable Code in Non-Executable Files Likelihood: High · Severity: Very High
- CAPEC-77 Manipulating User-Controlled Variables Likelihood: High · Severity: Very High
- CAPEC-242 Code Injection Likelihood: High · Severity: High
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.