How severe is CVE-2026-1839?

CVE-2026-1839 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-1839 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-1839?

CVE-2026-1839 primarily affects Huggingface Transformers. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-1839?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-1839 have an EU (EUVD) identifier?

Yes. CVE-2026-1839 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-19573.

When was CVE-2026-1839 published?

CVE-2026-1839 was published on 2026-04-07 and last updated on 2026-06-17.

CVE-2026-1839

CVE-2026-1839 is a high-severity vulnerability in Huggingface Transformers with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-502.

Key facts

Severity: High (CVSS 3.x base score 7.8)
EPSS exploit prediction: 0% (27th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-19573
Weakness: CWE-502
Affected product: Huggingface Transformers
Published: 2026-04-07
Last modified: 2026-06-17

Description

A vulnerability in the HuggingFace Transformers library, specifically in the `Trainer` class, allows for arbitrary code execution. The `_load_rng_state()` method in `src/transformers/trainer.py` at line 3059 calls `torch.load()` without the `weights_only=True` parameter. This issue affects all versions of the library supporting `torch>=2.2` when used with PyTorch versions below 2.6, as the `safe_globals()` context manager provides no protection in these versions. An attacker can exploit this vulnerability by supplying a malicious checkpoint file, such as `rng_state.pth`, which can execute arbitrary code when loaded. The issue is resolved in version v5.0.0rc3.

Frequently asked questions

What is CVE-2026-1839?: A vulnerability in the HuggingFace Transformers library, specifically in the `Trainer` class, allows for arbitrary code execution. The `_load_rng_state()` method in `src/transformers/trainer.py` at line 3059 calls `torch.load()` without the `weights_only=True` parameter. This issue affects all versions of the library supporting `torch>=2.2` when used with PyTorch versions below 2.6, as the `safe_globals()` context manager provides no protection in these versions. An attacker can exploit this vulnerability by supplying a malicious checkpoint file, such as `rng_state.pth`, which can execute arbitrary code when loaded. The issue is resolved in version v5.0.0rc3.
How severe is CVE-2026-1839?: CVE-2026-1839 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-1839 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-1839?: CVE-2026-1839 primarily affects Huggingface Transformers. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-1839?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-1839 have an EU (EUVD) identifier?: Yes. CVE-2026-1839 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-19573.
When was CVE-2026-1839 published?: CVE-2026-1839 was published on 2026-04-07 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:huggingface:transformers:*:*:*:*:*:*:*:*
cpe:2.3:a:huggingface:transformers:5.0.0:rc0:*:*:*:*:*:*
cpe:2.3:a:huggingface:transformers:5.0.0:rc1:*:*:*:*:*:*
cpe:2.3:a:huggingface:transformers:5.0.0:rc2:*:*:*:*:*:*

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