PYSEC-2026-3764 CVE-2026-74888 GHSA-743f-89fg-x288
openssl_encrypt versions before 1.4.0 use a non-standard PBKDF2 key derivation construction with iterations=1 per call in an outer loop, creating a KDF whose…
High
PyPI
- Severity
- 0.0 / 10
- High · CVSS 4.0
- Exploit chance (EPSS)
- 0.27%
- Chance of exploitation in the next 30 days. Higher than 19.56% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-327 Use of a Broken or Risky Cryptographic Algorithm
- Fix
1.4.0- Upgrade openssl-encrypt to this version or later
Description
openssl_encrypt versions before 1.4.0 use a non-standard PBKDF2 key derivation construction with iterations=1 per call in an outer loop, creating a KDF whose security properties have not been formally analyzed. Attackers can exploit this weakened key derivation to more efficiently crack passwords protecting legacy encrypted files compared to standard PBKDF2 implementations.
Affected versions
PyPI
| Package | Vulnerable | Fixed in |
|---|---|---|
| openssl-encrypt | < 1.4.0 |
1.4.0 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
openssl-encrypt PyPI → 1.4.0
- pip
pip install --upgrade "openssl-encrypt>=1.4.0"- poetry
poetry add "openssl-encrypt>=1.4.0"- uv
uv add "openssl-encrypt>=1.4.0"
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- None
- User interaction
- None
- Confidentiality (vulnerable system)
- High
- Integrity (vulnerable system)
- None
- Availability (vulnerable system)
- None
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
- Exploit maturity
- Not defined
- Scope
- X
CVSS 3.1 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Weakness
CWE-327: Use of a Broken or Risky Cryptographic Algorithm
The product uses a broken or risky cryptographic algorithm or protocol.
How to prevent it
- Architecture and Design: When there is a need to store or transmit sensitive data, use strong, up-to-date cryptographic algorithms to encrypt that data. Select a well-vetted algorithm that is currently considered to be strong by experts in the field, and use well-tested implementations. As with all cryptographic mechanisms, the source code should be available for analysis. For example, US government systems require FIPS 140-2 certification [REF-1192]. Do not develop custom or private cryptographic algorithms. They will likely be exposed to attacks that are well-understood by cryptographers. Reverse engineering techniques are mature. If the algorithm can be compromised if attackers find out how it works, then it is especially weak. Periodically ensure that the cryptography has not become obsolete. Some older algorithms, once thought to require a billion years of computing time, can now be broken in days or hours. This includes MD4, MD5, SHA1, DES, and other algorithms that were once regarded as strong. [REF-267]
- Architecture and Design: Ensure that the design allows one cryptographic algorithm to be replaced with another in the next generation or version. Where possible, use wrappers to make the interfaces uniform. This will make it easier to upgrade to stronger algorithms. With hardware, design the product at the Intellectual Property (IP) level so that one cryptographic algorithm can be replaced with another in the next generation of the hardware product.
- Architecture and Design: Carefully manage and protect cryptographic keys (see CWE-320). If the keys can be guessed or stolen, then the strength of the cryptography itself is irrelevant.
- Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482]. Industry-standard implementations will save development time and may be more likely to avoid errors that can occur during implementation of cryptographic algorithms. Consider the ESAPI Encryption feature.
- Implementation, Architecture and Design: When using industry-approved techniques, use them correctly. Don't cut corners by skipping resource-intensive steps (CWE-325). These steps are often essential for preventing common attacks.
References
Advisories
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| PYSEC-2026-3803 openssl_encrypt before 1.4.9 fails to validate KDF cost parameters in encrypted file metadata and keystore headers, allowing attackers to trigger unbounded… | High | Also affects openssl-encrypt |
| PYSEC-2026-3965 openssl_encrypt before 1.4.9 fails to validate the memory_cost parameter from identity file protection blocks, allowing attackers to trigger out-of-memory… | Medium | Also affects openssl-encrypt |
| PYSEC-2026-3802 openssl_encrypt before 1.4.9 executes untrusted third-party plugins with insufficient controls: the plugin signature policy defaulted to WARN, so an… | High | Also affects openssl-encrypt |
| PYSEC-2026-3801 openssl_encrypt (pip package openssl-encrypt) before 1.4.9 contains two weaknesses in the portable USB drive feature, whose threat model treats the removable… | Low | Also affects openssl-encrypt |
| PYSEC-2026-3800 openssl_encrypt (pip: openssl-encrypt) versions before 1.4.9 contain a path traversal flaw in PluginSandbox._is_safe_path, which authorized file access using a… | Medium | Also affects openssl-encrypt |
| PYSEC-2026-3964 openssl_encrypt (pip package openssl-encrypt) versions <= 1.4.8 do not redact the keyserver bearer token passed as the positional argument to 'keyserver… | Low | Also affects openssl-encrypt |
| PYSEC-2026-3799 openssl_encrypt (pip: openssl-encrypt) versions <= 1.4.8 use suffix-tolerant fingerprint matching in enroll_trust_key when binding a plugin-signing trust… | High | Also affects openssl-encrypt |
| PYSEC-2026-3781 openssl_encrypt before 1.4.9 fails to prevent namespace collisions between own identities and contacts in IdentityStore, allowing attackers to create shadowed… | Critical | Also affects openssl-encrypt |
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