PYSEC-2026-3965 CVE-2026-81720 GHSA-783h-8q2f-f762
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…
- Severity
- 0.0 / 10
- Medium · CVSS 4.0
- Exploit chance (EPSS)
- 0.18%
- Chance of exploitation in the next 30 days. Higher than 8.14% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-400 Uncontrolled Resource Consumption
- Fix
1.4.9- Upgrade openssl-encrypt to this version or later
Description
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 conditions during key derivation. Attackers with write access to local identity stores can craft malicious identity files with excessive memory_cost values that cause the host to crash when unlocking identities before authentication.
Affected versions
PyPI
| Package | Vulnerable | Fixed in |
|---|---|---|
| openssl-encrypt | < 1.4.9 |
1.4.9 |
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 → 1.4.9
- pip
pip install --upgrade "openssl-encrypt>=1.4.9"- poetry
poetry add "openssl-encrypt>=1.4.9"- uv
uv add "openssl-encrypt>=1.4.9"
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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
- Local
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- None
- User interaction
- None
- Confidentiality (vulnerable system)
- None
- Integrity (vulnerable system)
- None
- Availability (vulnerable system)
- High
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
- Exploit maturity
- Not defined
- Scope
- X
CVSS 3.1 6.2
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Weakness
CWE-400: Uncontrolled Resource Consumption
The product does not properly control the allocation and maintenance of a limited resource.
How to prevent it
- Architecture and Design: Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place. The login application should be protected against DoS attacks as much as possible. Limiting the database access, perhaps by caching result sets, can help minimize the resources expended. To further limit the potential for a DoS attack, consider tracking the rate of requests received from users and blocking requests that exceed a defined rate threshold.
- Architecture and Design: Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, or uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed. The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question. The second solution is simply difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.
- Architecture and Design: Ensure that protocols have specific limits of scale placed on them.
- Implementation: Ensure that all failures in resource allocation place the system into a safe posture.
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-2026-3802 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 |
| PYSEC-2026-3780 openssl-encrypt before 1.4.9 fails to redact the file password in its --debug argv dump when the password is supplied via bundled short-option spellings (e.g. | High | Also affects openssl-encrypt |
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