CVE-2026-33936

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5%, top 61% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Elevated
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
5.3
EG Score
5.3(medium)
EG Risk
55(Attend)
EG Risk 55/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity53% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
40%
KEV
Not listed

Published

March 27, 2026

Last Modified

June 17, 2026

Advisory Details (3)

Auto-updated Aug 6, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_release, github.
github Patch Available🟡 PoC Available

Malformed DER can raise IndexError in SigningKey.from_der(); DER OCTET STRING length truncation not rejected · Advisory · tlsfuzzer/python-ecdsa · GitHub

https://github.com/tlsfuzzer/python-ecdsa/security/advisories/GHSA-9f5j-8jwj-x28g
github_release Patch Available

0.19.2

Patch available: tlsfuzzer/python-ecdsa python-ecdsa-0.19.2

https://github.com/tlsfuzzer/python-ecdsa/releases/tag/python-ecdsa-0.19.2
github_commit Patch Available

commit bd66899550d7 (tlsfuzzer/python-ecdsa)

Patch available: tlsfuzzer/python-ecdsa python-ecdsa-0.19.2 (contains commit bd66899550d7)

https://github.com/tlsfuzzer/python-ecdsa/commit/bd66899550d7185939bf27b75713a2ac9325a9d3

Vendor Advisories for CVE-2026-33936(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
python-ecdsa0.16.1-1 ... 0.19.2-1 (13 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
python-ecdsa0.18.0-3 ... 0.19.2-1 (7 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
python-ecdsa0.19.1-1, 0.19.1-1+deb13u1, 0.19.2-1——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
python-ecdsa0.19.1-10.19.2-1—
PyPI(1)
PackageVulnerable rangeFixed inDependents
ecdsa0.10 ... 0.9 (22 versions)0.19.2—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 30× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-17 19:30 UTCEPSS rescore
  4. 2026-09-16 14:08 UTCEPSS rescore
  5. 2026-09-16 05:15 UTCEPSS rescore
  6. 2026-09-15 03:11 UTCEPSS rescore
  7. 2026-09-13 16:47 UTCEPSS rescore
  8. 2026-09-12 15:01 UTCEPSS rescore
  9. 2026-09-11 14:53 UTCEPSS rescore
  10. 2026-09-11 09:37 UTCEPSS rescore
  11. 2026-09-10 09:34 UTCEPSS rescore
  12. 2026-09-08 22:00 UTCEPSS rescore
  13. 2026-09-07 16:01 UTCEPSS rescore
  14. 2026-09-06 13:47 UTCEPSS rescore
  15. 2026-09-04 05:06 UTCEPSS rescore
  16. 2026-09-02 14:12 UTCEPSS rescore
  17. 2026-09-02 13:04 UTCOSV refresh
  18. 2026-09-01 13:53 UTCEPSS rescore
  19. 2026-09-01 04:39 UTCEPSS rescore
  20. 2026-08-30 19:17 UTCEPSS rescore
  21. 2026-08-30 01:22 UTCEPSS rescore
  22. 2026-08-28 21:41 UTCEPSS rescore
  23. 2026-08-27 14:25 UTCEPSS rescore
  24. 2026-08-26 14:46 UTCEPSS rescore
  25. 2026-08-25 13:49 UTCEPSS rescore
Show 47 more
  1. 2026-08-24 14:17 UTCEPSS rescore
  2. 2026-08-23 00:19 UTCEPSS rescore
  3. 2026-08-21 23:49 UTCEPSS rescore
  4. 2026-08-20 22:55 UTCEPSS rescore
  5. 2026-08-20 22:55 UTCEPSS rescore
  6. 2026-08-19 17:03 UTCEPSS rescore
  7. 2026-08-18 13:48 UTCEPSS rescore
  8. 2026-08-17 13:47 UTCEPSS rescore
  9. 2026-08-16 14:56 UTCEPSS rescore
  10. 2026-08-16 09:56 UTCEG score recompute
  11. 2026-08-16 09:56 UTCVendor advisory
  12. 2026-08-16 02:14 UTCEPSS rescore
  13. 2026-08-15 01:30 UTCEPSS rescore
  14. 2026-08-14 06:15 UTCEG score recompute
  15. 2026-08-14 06:15 UTCVendor advisory
  16. 2026-08-13 22:00 UTCEPSS rescore
  17. 2026-08-12 20:33 UTCEG score recompute
  18. 2026-08-12 20:33 UTCVendor advisory
  19. 2026-08-12 13:50 UTCEPSS rescore
  20. 2026-08-11 06:15 UTCEG score recompute
  21. 2026-08-11 06:15 UTCVendor advisory
  22. 2026-08-11 00:00 UTCEPSS rescore
  23. 2026-08-10 06:02 UTCEG score recompute
  24. 2026-08-10 06:02 UTCVendor advisory
  25. 2026-08-09 13:46 UTCEPSS rescore
  26. 2026-08-09 05:48 UTCEG score recompute
  27. 2026-08-09 05:48 UTCVendor advisory
  28. 2026-08-08 16:37 UTCEPSS rescore
  29. 2026-08-07 16:15 UTCEG score recompute
  30. 2026-08-07 16:15 UTCVendor advisory
  31. 2026-08-06 13:46 UTCEPSS rescore
  32. 2026-08-06 00:44 UTCEG score recompute
  33. 2026-08-06 00:44 UTCVendor advisory
  34. 2026-08-05 19:17 UTCEPSS rescore
  35. 2026-08-04 15:10 UTCEPSS rescore
  36. 2026-08-04 10:38 UTCEPSS rescore
  37. 2026-08-03 23:06 UTCEG score recompute
  38. 2026-08-03 10:36 UTCEPSS rescore
  39. 2026-08-02 15:09 UTCEG score recompute
  40. 2026-08-02 15:09 UTCVendor advisory
  41. 2026-08-02 02:27 UTCEPSS rescore
  42. 2026-08-01 04:16 UTCEPSS rescore
  43. 2026-07-30 16:28 UTCEPSS rescore
  44. 2026-07-30 01:30 UTCEPSS rescore
  45. 2026-07-27 14:13 UTCEPSS rescore
  46. 2026-07-27 12:50 UTCEG score recompute
  47. 2026-07-27 12:50 UTCVendor advisory

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-33936?
CVE-2026-33936 is a medium vulnerability published on March 27, 2026. 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…
When was CVE-2026-33936 disclosed?
CVE-2026-33936 was first published in the National Vulnerability Database on March 27, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-33936 actively exploited?
CVE-2026-33936 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 59.7% of all scored CVEs.
What is the CVSS score of CVE-2026-33936?
CVE-2026-33936 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-33936?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-33936, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-33936

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