Short answer. Yes. Article 2117 lets any third person who has a right in or to the pledged thing, such as a second pledgee or a co-owner, pay off the principal obligation once it falls due. Paying protects your own security interest from being wiped out at the first creditor's public auction.
What the law says
Any third person who has any right in or to the thing pledged may satisfy the principal obligation as soon as the latter becomes due and demandable.
Civil Code, Article 2117 — Third Person's Right to Satisfy the Debt. Read the full provision →
Who counts as a third person with a right in the thing
Article 2117 is not a general rule letting any stranger pay someone else's debt. It is narrower: it names a third person who already has a right in or to the very thing pledged, someone like a second pledgee holding a subsequent security interest in the same item, or a co-owner of the pledged property.
That existing stake is what gives this person standing to step in and pay, because the first pledgee's auction would otherwise threaten a right that already belongs to them.
Why this matters for a second pledgee
If a debtor pledges an item to a first lender and later pledges the same item, or an interest in it, to a second lender, the second lender's security is only as good as what survives the first pledge. A public auction under the first pledge can wipe out or complicate the second lender's claim.
By paying off the first creditor once the debt becomes due, the second lender removes that threat and can then look to the debtor to recover what was paid, effectively stepping into the first creditor's shoes as far as the security is concerned.
Timing: the debt must already be due
The right to pay under Article 2117 only arises once the principal obligation becomes due and demandable. A second pledgee cannot force an early payoff of a loan that has not yet matured just because it would be convenient.
Once the first obligation is due, though, the second pledgee does not need to wait for a formal demand or auction notice before stepping in and settling it.
What happens after payment
Once the third person pays the principal obligation, the first pledge is satisfied and the first creditor's rights over the thing end. The person who paid can then recover the amount from the debtor, and their own security interest in the item is no longer at risk from the first creditor's claim. If the debtor never reimburses the amount paid, the second pledgee's recourse is an ordinary collection action against the debtor's other assets, since satisfying the first pledge does not itself convert the debtor's original obligation into anything more than an ordinary debt owed to the person who paid it.