Unsafe Deserialization in stanza (CVE-2026-54499)
Summary
Vulnerability in stanza (CVE-2026-54499). Successful exploitation can lead to full system takeover. Exploitable via pickle.UnpicklingError. Mitigation: upgrade to 1.12.2 or later.
Original description
The description as published by the source.
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.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-54499 has been found in stanza.
Attackers can target a specific entry point like pickle.UnpicklingError over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 7.5/10.
What to do: upgrade stanza to 1.12.2 or later.
If unsure, ask your IT team or search "stanza CVE-2026-54499" on the vendor's site.
CVE-2026-54499 (stanza) — CWE-502 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: pickle.UnpicklingError / UnpicklingError / torch.load / __reduce__
Patched: 1.12.2 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Unsafe deserialization (CWE-502) exists in stanza. Attackers reach the vulnerable code path via pickle.UnpicklingError without authentication.
Check the vendor advisory for the affected versions of stanza. Attack surface: pickle.UnpicklingError / UnpicklingError / torch.load / __reduce__.
Severity: High (CVSS 7.5/10). Successful exploitation can lead to full system takeover.
Update to 1.12.2.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'stanza' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'stanza' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
stanzaを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade stanza to 1.12.2ステージング環境で 1.12.2 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- patch github.com
- patch github.com
- web github.com
- web github.com