Disentangling In-Language Alignment and Cross-Lingual Safety Borrowing in Low-Resource Languages

Zeguang Huang, Zhenma Spenpa, Mio Yip Sien Chu, Xi Cao, Nuo Qun, Nyima Tashi


Abstract
We study two modes of low-resource language safety: in-language alignment, where models refuse harmful instructions in the target language, and cross-lingual safety borrowing, where they rely on a better-aligned proximate high-resource language, including via response-language fallback. We evaluate 11 commercial APIs on English, Mandarin, Cantonese, Tibetan, and Russian, plus 3 Tibetan-specialized open-source models, using native-speaker-verified datasets. Results reveal two patterns: Tibetan, for which response-language fallback provides limited aggregate protection in our setting, shows a safety cliff with ASR of 12.69–60.96%, far above English; Cantonese, which shares script and vocabulary with Mandarin, keeps aggregate ASR in single digits, but Cantonese-reply ASR exceeds aggregate ASR for all 11 models (sign test, p < 0.001), exposing in-language safety gaps concealed by aggregate metrics. We release Cantonese-AdvBench and Tibetan-AdvBench.
Anthology ID:
2026.findings-emnlp.778
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
16447–16459
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.778/
DOI:
10.18653/2026.findings-emnlp.778
Bibkey:
Cite (ACL):
Zeguang Huang, Zhenma Spenpa, Mio Yip Sien Chu, Xi Cao, Nuo Qun, and Nyima Tashi. 2026. Disentangling In-Language Alignment and Cross-Lingual Safety Borrowing in Low-Resource Languages. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 16447–16459, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Disentangling In-Language Alignment and Cross-Lingual Safety Borrowing in Low-Resource Languages (Huang et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.778.pdf