Despite the best efforts of its writers, software has vulnerabilities, and GitHub is no exception. Finding, fixing, and learning from past bugs is a critical part of keeping our users and their data safe on the Internet. Two years ago, we launched the GitHub Security Bug Bounty and it’s been an incredible success. By rewarding the talented and dedicated researchers in the security industry, we discover and fix security vulnerabilities before they can be exploited.

Bugs squashed

Bounty Submissions Per Week

Of 7,050 submissions in the past two years, 1,772 warranted further review, helping us to identify and fix vulnerabilities spanning all of the OWASP top 10 vulnerability classifications. 58 unique researchers earned a cumulative $95,300 for the 102 medium to high risk vulnerabilities they reported. This chart shows the breakdown of payouts by severity and OWASP classification:

A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A0 Sum
Low 4 5 11.5 1 8 11 5 7 3 3.5 1 60
Medium 2 1 12 0 1 1 5 1 0 3 0 26
High 2 2 3.5 0 2 1 0 0.5 0 0 2 13
Critical 3 0 0 0 0 0 0 0 0 0 0 3
Sum 11 8 27 1 11 13 10 8.5 4 6.5 3 102


We love it when a reported vulnerability ends up not being our fault. @kelunik and @bwoebi reported a browser vulnerability, causing GitHub’s cookies to be sent to other domains. @ealf reported a browser bug, bypassing our JavaScript same-origin policy checks. We were able to protect our users from these vulnerabilities months before the browser vendors released patches.

Another surprising bug was reported by @cryptosense, who found that some RSA key generators were creating SSH keys that were trivially factorable. We ended up finding and revoking 309 weak RSA keys and now have validations checking if keys are factorable by the first 10,000 primes.

In the first year of the bounty program, we saw reports mostly about our web services. In 2015, we received a number of reports for vulnerabilities in our desktop apps. @tunz reported a clever exploit against GitHub for Mac, allowing remote code execution. Shortly thereafter, @joernchen reported a similar bug in GitHub for Windows, following up a few months later with a separate client-side remote code execution vulnerability in Git Large File Storage (LFS).

Hacking with purpose

In 2015 we saw an amazing increase in the number of bounties donated to a good cause. GitHub matches bounties donated to 501(c)(3) organizations, and with the help of our researchers we contributed to the EFF, Médecins Sans Frontières, the Ada Initiative, the Washington State Burn Foundation, and the Tor Project. A big thanks to @ealf, @LukasReschke, @arirubinstein, @cryptosense, @bureado, @vito, and @s-rah for their generosity.

Get involved

In the first two years of the program, we paid researchers nearly $100,000. That’s a great start, but we hope to further increase participation in the program. So, fire up your favorite proxy and start poking at When you find a vulnerability, report it and join the ranks of our leaderboard. Happy hacking!