Vulnerability in pymonocypher
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-2026-53720 has been found in pymonocypher.
Risk of unauthorized operations or information disclosure.
What to do: upgrade pymonocypher to 4.0.2.8 or later.
If unsure, ask your IT team or search "pymonocypher CVE-2026-53720" on the vendor's site.
CVE-2026-53720 (pymonocypher) — CWE-122
Patched: 4.0.2.8 — 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.
A vulnerability (CWE-122) exists in pymonocypher.
Check the vendor advisory for the affected versions of pymonocypher.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 4.0.2.8.
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 'pymonocypher' . 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
-
1
Identify exposureidentify
grep -r 'pymonocypher' . | 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
pymonocypherを grep し、稼働しているサービス・バージョンを把握する。 -
2
Apply patchpatch
Upgrade pymonocypher to 4.0.2.8ステージング環境で 4.0.2.8 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。
-
3
Post-deployment verificationverify
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
| Ecosystem | Package | Affected | Fixed |
|---|---|---|---|
| pip | pymonocypher |
< 4.0.2.8 |
4.0.2.8 |
| PyPI | pymonocypher |
< 4.0.2.8 |
4.0.2.8 |
Original description The description as published by the source.
pymonocypher uses cython to wrap the Monocypher C library. Prior to version 4.0.2.8, the argon2i_32 implementation does not check the nb_blocks size. If the caller does not provide a sufficiently large buffer based on the API contract, then argon2i_32 will write past the end of the buffer and possibly corrupt the heap. This issue has been patched in version 4.0.2.8.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- patch github.com
- web github.com
- web github.com