Think you're having a bad week? Spare a thought for Robin Seggelmann, the German programmer who accidentally introduced the Heartbleed bug and unsecured thousands of supposedly secure websites in the process.

The erroneous code was submitted as part of Seggelmann's PhD studies at 11.59pm on New Year's Eve 2011 - but it was only discovered in recent weeks.

Oversight

"I am responsible for the error because I wrote the code and missed the necessary validation by an oversight," he told The Guardian.

"Unfortunately, this mistake also slipped through the review process and therefore made its way into the released version."

Also known as the "Oops, my bad!" admission, although a whole host of other people managed to miss the mistake over the course of the following years.

"I can only assume that it took so long because it's in a new feature which is not widely used and not a conceptual, but a simple programming error."