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3 vulnerabilities by tlsfuzzer
CVE-2026-33936 (GCVE-0-2026-33936)
Vulnerability from cvelistv5 – Published: 2026-03-27 22:08 – Updated: 2026-04-01 13:44
VLAI?
Title
python-ecdsa: Denial of Service via improper DER length validation in crafted private keys
Summary
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.
Severity ?
5.3 (Medium)
CWE
Assigner
References
| URL | Tags | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
|||||||||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| tlsfuzzer | python-ecdsa |
Affected:
< 0.19.2
|
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CVE-2024-23342 (GCVE-0-2024-23342)
Vulnerability from cvelistv5 – Published: 2024-01-22 23:09 – Updated: 2025-05-30 14:21
VLAI?
Title
python-ecdsa vulnerable to Minerva attack on P-256
Summary
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). Versions 0.18.0 and prior are vulnerable to the Minerva attack. As of time of publication, no known patched version exists.
Severity ?
7.4 (High)
CWE
Assigner
References
| URL | Tags | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
||||||||||||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| tlsfuzzer | python-ecdsa |
Affected:
<= 0.18.0
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CVE-2020-26263 (GCVE-0-2020-26263)
Vulnerability from cvelistv5 – Published: 2020-12-21 16:55 – Updated: 2024-08-04 15:56
VLAI?
Title
RSA vulnerability in tslite-ng
Summary
tlslite-ng is an open source python library that implements SSL and TLS cryptographic protocols. In tlslite-ng before versions 0.7.6 and 0.8.0-alpha39, the code that performs decryption and padding check in RSA PKCS#1 v1.5 decryption is data dependant. In particular, the code has multiple ways in which it leaks information about the decrypted ciphertext. It aborts as soon as the plaintext doesn't start with 0x00, 0x02. All TLS servers that enable RSA key exchange as well as applications that use the RSA decryption API directly are vulnerable. This is patched in versions 0.7.6 and 0.8.0-alpha39. Note: the patches depend on Python processing the individual bytes in side-channel free manner, this is known to not the case (see reference). As such, users that require side-channel resistance are recommended to use different TLS implementations, as stated in the security policy of tlslite-ng.
Severity ?
7.5 (High)
CWE
- CWE-326 - Inadequate Encryption Strength
Assigner
References
| URL | Tags | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
||||||||||||||||||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| tlsfuzzer | tlslite-ng |
Affected:
< 0.7.6
Affected: >= 0.8.0-alpha1, < 0.8.0-alpha39 |
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"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2020-26263",
"datePublished": "2020-12-21T16:55:18.000Z",
"dateReserved": "2020-10-01T00:00:00.000Z",
"dateUpdated": "2024-08-04T15:56:03.863Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}