openssl_encrypt: Improper Verification of Cryptographic Signature
CVE-2026-74876 is a critical-severity improper verification of cryptographic signature vulnerability in openssl_encrypt from Jahlives, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 1.4.0 as the first without the flaw, so updating openssl_encrypt to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.35% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update openssl_encrypt to 1.4.0 or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Jahlives | openssl_encrypt | before 1.4.0 | 1.4.0 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 9.3 | Critical | CNA (vulncheck.com) |
| CVSS 3.1 | 9.8 | Critical | CNA (vulncheck.com) |
Official description
openssl_encrypt versions before 1.4.0 contain a vulnerability in PublicKeyBundle.from_dict() that creates key bundles from untrusted data without verifying signatures. Attackers can call from_dict() followed by to_identity() without signature verification to encrypt data using attacker-controlled public keys, leaking secrets.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Verification of Cryptographic Signature
The product does not verify, or incorrectly verifies, the cryptographic signature for data.
More Improper Verification of Cryptographic Signature vulnerabilities (CWE-347)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- vulncheck.com/advisories/openssl-encrypt-before-unverified-key-bundle-encryptionThird Party Advisory
Other vulnerabilities in openssl_encrypt
- 7.5 High severity
- 7.8 High severity
- 7.5 High severity
- 7.0 High severity
- 9.8 Critical severity
- 7.5 High severity
Recent Improper Verification of Cryptographic Signature vulnerabilities
- 9.8 Critical severity
- 8.1 High severity
- 7.5 High severity
- 7.5 High severity
- 8.4 High severity
- 7.5 High severity
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