E3 ubiquitin-protein ligase which regulates the IFN-beta production and antiviral response downstream of various DNA-encoded pattern-recognition receptors (PRRs). Promotes nuclear IRF3 ubiquitination and proteasomal degradation. Bridges together TBK1 and NEMO during the innate response to viral infection leading to the activation of TBK1. S-ubiquitinyl-[E2 ubiquitin-conjugating enzyme]-L-cysteine + [acceptor protein]-L-lysine = [E2 ubiquitin-conjugating enzyme]-L-cysteine + N(6)-ubiquitinyl-[acceptor protein]-L-lysine. Interacts with TBK1; this interaction bridges together TBK1 and NEMO in order to activate TBK1 (PubMed:26611359). Interacts with INCA1 (PubMed:21750715). Viral infection mediates TRIM26 nuclear translocation. Autoubiquitinates upon viral infection. In turn, autoubiquitinated TRIM26 recruits NEMO and bridges TBK1-NEMO interaction. Belongs to the TRIM/RBCC family.