Estar, o poner, en duda algo que antes era claro y seguro.

DRAE. Diccionario de la Lengua Española.

Soslayar o violar los mecanismos o procedimientos  de seguridad de un sistema, recurso o activo con el resultado de desproteger a los mismos. [Ribagorda:1997]

1. Resultado de un incumplimiento o violación de las medidas de seguridad, por el que determinada información ha quedado desprotegida.

2. Documento en el que una persona reconoce haber sido instruida en las medidas de seguridad vigentes y se compromete a aplicarlas.

[CESID:1997]

To bring somebody/something/yourself into danger or under suspicion, especially by acting in a way that is not very sensible.

Oxford Advanced Learner's Dictionary.

compromise of security that leads to the accidental or unlawful destruction, loss, alteration, unauthorized disclosure of, or access to protected data transmitted, stored or otherwise processed [ISO-27050:2015]

Disclosure of information to unauthorized persons, or a violation of the security policy of a system in which unauthorized intentional or unintentional disclosure, modification, destruction, or loss of an object may have occurred. [CNSSI_4009:2010]

(I) A security violation in which a system resource is exposed, or is potentially exposed, to unauthorized access. (Compare: data compromise, exposure, violation.) [RFC4949:2007]

1. (I) A security incident in which information is exposed to potential unauthorized access, such that unauthorized disclosure, alteration, or use of the information might have occurred. (Compare: security compromise, security incident.)

2. (O) /U.S. DoD/ A "compromise" is a "communication or physical transfer of information to an unauthorized recipient." [DoD5]

3. (O) /U.S. Government/ "Type of [security] incident where information is disclosed to unauthorized individuals or a violation of the security policy of a system in which unauthorized intentional or unintentional disclosure, modification, destruction, or loss of an object may have occurred." [C4009]

[RFC4949:2007]

The unauthorized disclosure, modification, substitution or use of sensitive data (e.g., keying material and other security related information). [NIST-SP800-57:2007]

the unauthorised disclosure, modification, substitution, or use of CSPs or the unauthorised modification or substitution of PSPs.

CSP - critical security parameter - security related information whose disclosure or modification can compromise the security of a cryptographic module.

EXAMPLE: Secret and private cryptographic keys, authentication data such as passwords, PINs, certificates or other trust anchors.

NOTE. A CSP may be plaintext or encrypted.

PSP - public security parameter

security related public information whose modification can compromise the security of a cryptographic module.

EXAMPLE: Public cryptographic keys, public key certificates, self-signed certificates, trust anchors, and one time passwords associated with a counter.

[ISO-19790:2006]

Compromise denotes a situation when -due to a breach of security or adverse activity (such as espionage, acts of terrorism, sabotage or theft)- classified information has lost its confidentiality, integrity or availability, or supporting services and resources have lost their integrity or availability. This includes loss, disclosure to unauthorised individuals (e.g. through espionage or to the media) unauthorised modification, destruction in an unauthorised manner, or denial of service.

the unauthorized disclosure, modification, substitution, or use of sensitive data (including plaintext cryptographic keys and other CSPs). [FIPS-140-2:2001]

Also referred to as “data compromise,” or “data breach.” Intrusion into a computer system where unauthorized disclosure/theft, modification, or destruction of cardholder data is suspected.

https://www.pcisecuritystandards.org/security_standards/glossary.php

The unauthorized access to, disclosure, destruction, removal, modification, use or interruption of assets or information.

http://www.tbs-sct.gc.ca/pol/doc-eng.aspx?id=16578

Également dénommé «compromission des données» ou «atteinte à la protection des données». Intrusion dans un système informatique lorsque l’on soupçonne une divulgation/un vol, une modification ou la destruction non autorisés des données du titulaire de carte.

http://fr.pcisecuritystandards.org/