CyberSecBulletin
CVE-2026-81700NVD status: Analyzed

openssl_encrypt: Improper Verification of Cryptographic Signature

CVE-2026-81700 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 1.4.9 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.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update openssl_encrypt to 1.4.9 or a later version.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Jahlivesopenssl_encryptbefore 1.4.91.4.9

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 systemScoreSeverityScored by
CVSS 4.09.3CriticalCNA (vulncheck.com)
CVSS 3.19.8CriticalCNA (vulncheck.com)

Official description

openssl_encrypt versions before 1.4.9 contain a signature verification vulnerability in gpg_runner.verify_detached that accepts revoked and expired keys by only checking VALIDSIG status without inspecting REVKEYSIG, EXPKEYSIG, or gpg exit codes. Attackers holding compromised-then-revoked signing keys or expired project keys can bypass signature verification to execute malicious plugins in the host process.

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

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in openssl_encrypt

All openssl_encrypt vulnerabilities

Recent Improper Verification of Cryptographic Signature vulnerabilities

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