vault-java-driver, a Java client for HashiCorp Vault, parses Vault's JSON responses with a vendored minimal-json parser that has no nesting depth limit. A deeply nested value raises a StackOverflowError, which escapes catch (Exception) handlers and kills the reading thread. A Vault token that can write but not read a KV v2 path can store such a value there, so every later read of that path through the driver fails. This requires Vault 1.19.x or earlier, because 1.20 and later reject values nested deeper than 298 levels. This issue affects io.github.jopenlibs:vault-java-driver 5.2.0 through 6.2.3 and is fixed in 7.0.0.
Upgrade io.github.jopenlibs:vault-java-driver to 7.0.0 or later.