XRP Ledger Closes Burn Bug That Let Delegates Mint Tokens

The XRP Ledger activated the fixCleanup3_4_0 amendment on Nov. 4 at 2:52 p.m. UTC, closing a loophole that let a delegate cleared only to burn tokens create new ones in some cases, XRPSCAN and Unchained report.

The amendment shipped with xrpld 3.4.0, the reference server release published Sept. 17. RippleX's 3.4.0 release post says the bundle now "Rejects PaymentBurn payments that cross a zero balance." XRPSCAN lists enablement in the flag ledger around 108,112,128, with 33 of 35 trusted validators voting for it.

What PaymentBurn was supposed to do

Permission delegation lets one XRPL account hand specific powers to another. PaymentBurn is meant to let a delegate remove fungible tokens on an issuer's behalf: trust-line tokens and multi-purpose tokens (MPTs). Before the fix, documentation warned that a delegate with that permission was also able to mint new tokens in certain circumstances. Other granular permissions were not affected, and the native XRP supply was not involved, Unchained reported from the docs and the release post.

Until activation, the practical safeguard was a line in the docs asking issuers not to delegate PaymentBurn at all. With the amendment live, the ledger itself rejects the zero-crossing burn payment that created the mint path.

XRPL amendments need more than 80% of trusted validators for two straight weeks. XRPSCAN shows majority support from Oct. 21 through enablement. Unchained said an earlier run that began Oct. 9 lost the majority on Oct. 21 about 12 days in, then restarted the same day.

The change is separate from the payment-engine integer overflow that had a path to affect XRP's fixed supply. That issue was patched in xrpld 3.4.1 without an amendment vote, Unchained reported earlier. XRP traded near $1.32 at 5:57 a.m. ET Thursday, up about 2.2% over 24 hours, per CoinGecko.

In our opinion: the bigger story is how long the warning-label period lasted. Delegation was live on mainnet while the only guardrail was documentation telling issuers not to grant PaymentBurn. Issuers that want a separate burn account can now do it under protocol rules instead of a docs caveat. The next check is whether any issuer that delayed delegation turns it on now that the fix is live.