# CVE-2026-33936: python-ecdsa: The `ecdsa` PyPI package is a pure Python implementation of ECC (Elliptic Curve Cryptography) with support for ECDSA...

CVE-2026-33936 is fixed in python-ecdsa on 1 platform, first by DEBIAN-CVE-2026-33936, released March 27, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-33936
- Priority: Routine
- CVSS: 5.3 (medium)
- EPSS: 0.0049
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Mar 27, 2026

## Description

The `ecdsa` PyPI package is a pure Python implementation of ECC (Elliptic Curve Cryptography) with support for ECDSA (Elliptic Curve Digital Signature Algorithm), EdDSA (Edwards-curve Digital Signature Algorithm) and ECDH (Elliptic Curve Diffie-Hellman). Prior to version 0.19.2, an issue in the low-level DER parsing functions can cause unexpected exceptions to be raised from the public API functions. `ecdsa.der.remove_octet_string()` accepts truncated DER where the encoded length exceeds the available buffer. For example, an OCTET STRING that declares a length of 4096 bytes but provides only 3 bytes is parsed successfully instead of being rejected. Because of that, a crafted DER input can cause `SigningKey.from_der()` to raise an internal exception (`IndexError: index out of bounds on dimension 1`) rather than cleanly rejecting malformed DER (e.g., raising `UnexpectedDER` or `ValueError`). Applications that parse untrusted DER private keys may crash if they do not handle unexpected exceptions, resulting in a denial of service. Version 0.19.2 patches the issue.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | python-ecdsa Debian 13.5 (trixie) | 0.19.1-1+deb13u1 | [DEBIAN-CVE-2026-33936](https://patchblox.com/security/data/fix/linux/debian-cve-2026-33936.md) | Mar 27, 2026 |
| Linux | python-ecdsa Debian 14 | 0.19.2-1 | [DEBIAN-CVE-2026-33936](https://patchblox.com/security/data/fix/linux/debian-cve-2026-33936.md) | Mar 27, 2026 |
| Linux | python-ecdsa opensuse-leap 15.6 | 0.18.0-150400.12.6.1 | [SUSE-SU-2026:1436-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1436-1.md) | Apr 17, 2026 |
| Linux | python-ecdsa opensuse-leap 16.0 | 0.19.1-160000.4.1 | [OPENSUSE-SU-2026:21078-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21078-1.md) | Jun 18, 2026 |
| Linux | python-ecdsa sles 15.7 | 0.13.3-150000.3.10.1 | [SUSE-SU-2026:1608-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1608-1.md) | Apr 24, 2026 |
| Linux | python-ecdsa sles 16.0 | 0.19.1-160000.4.1 | [SUSE-SU-2026:22158-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22158-1.md) | Jun 18, 2026 |

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Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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