openssl_encrypt CVE-2026-81706

Exploitation requires two concrete conditions drawn from the description: (1) the attacker must be able to create a contact entry in the target's IdentityStore whose namespace collides with an existing own identity (identity shadowing), and (2) the corresponding own identity must subsequently be deleted, which is the event that makes the shadowed contact resolve to the attacker's keys. The limiting factor is that the payload is dormant and only activates on the victim-controlled deletion of the matching own identity - the attacker cannot force this timing - so despite the PR:N/UI:N rating, real exploitation depends on both getting a colliding contact accepted and the victim later removing the shadowed own identity.

The supplied CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H, 9.3) rates this as network-reachable and unauthenticated with high impact across all three dimensions, but the description reveals meaningful preconditions that temper raw severity: the attacker must first get a colliding contact entry into the victim's IdentityStore, and exploitation only 'fires' when the victim later deletes the matching own identity - a specific, victim-driven event rather than an at-will attacker action. There is no EPSS score, no KEV listing, and no evidence of a public POC in the provided data, so this is best treated as a high-impact-but-not-yet-demonstrated cryptographic weakness rather than a mass-exploitation event. That said, because the failure mode is silent - encrypted files simply resolve to the wrong keys with no user-visible error - any operator relying on openssl_encrypt for at-rest or in-transit file confidentiality should treat the upgrade to 1.4.9 as urgent, since the damage (attacker-decryptable files) is discovered only after the fact. Note the tension between the flat AT:N/AC:L rating and the description's staged 'delete the own identity' trigger; a defender should read real-world exploit complexity as higher than the vector alone suggests.

An attacker submits or otherwise injects a contact into the victim's IdentityStore whose namespace identifier deliberately collides with one of the victim's own identities; the entry stays invisible because the own identity takes precedence. Later, when the victim retires or deletes that own identity, the shadowed contact becomes the active resolution and points at the attacker's key, so every file the victim now encrypts for that identity is silently encrypted to the attacker. No public POC is identified at time of analysis; the network attack vector and low base complexity mean the hard part for the attacker is planting the entry and waiting for the deletion trigger.