One of the first releases in the High Republic initiative has confirmed a new Sith lightsaber in Star Wars canon, one that didn't exist in Legends either. It's an exciting time for Star Wars fans; not only is Lucasfilm developing 10 new Star Wars TV shows, as well as a handful of movies with some of the industry's most noteworthy filmmakers, but the company is also working to explore a new era of the timeline - the High Republic, which takes place hundreds of years before the prequels.
Charles Soule's Light of the Jedi is the first adult novel to release as part of the High Republic project. Its purpose is to open up this era of the galaxy to readers and lay the foundation for a new emerging threat: the Nihil. Given the state of the Jedi Order, as well as the galaxy as a whole, was remarkably different at the time compared to the era of the Galactic Republic, various pieces of the story are new to canon - and one item, in particular, opens up new possibilities of Sith weapons as well as lightsabers.
In the new story, Jedi Master Jora Malli used her lightsaber to activate her Vector - in this era, a Jedi's lightsaber could also double as a key for their starfighter - which emitted a white light. As a brief note, Light of the Jedi revealed that Malli obtained the white lightsaber color by repurposing the kyber crystal she found inside a Sith lightspear. This is notably different from the lightstaff - an armored wooden staff imbued with the Force - and lightsaber pikes, which in canon are double-bladed lightsabers with longer hilts that are used by Jedi Temple Guards, but in Legends are long staffs with a short plasma beam on one end (pictured below).
Unfortunately, there aren't any pictures of the lightspear in Light of the Jedi, but it's not difficult to imagine what it looks like. What's more, the fact that the novel makes it a point to say the lightspear had a kyber crystal in it, it's enough to identify the weapon as a type of lightsaber, one that hasn't appeared in any other medium yet. And on top of that, Jora Malli managed to use the kyber crystal for her own lightsaber; it's usually the other way around.
In Star Wars canon, the way Dark Jedi and Sith Lords are able to produce a red color for their lightsabers is by bleeding the crystal - in a way imbuing it with the dark side of the Force. In this particular case, Master Malli purged the dark side and the "rage and pain instilled in it," which changed the crystal's color from blood-red to white. This is similar to what Ahsoka Tano did to obtain her white lightsabers, purifying the kyber crystals used by the Inquistor Sixth Brother. Whether or not this act becomes more commonplace in Star Wars remains to be seen, as does whether the lightspear shows up elsewhere.