MicroPython vs Erlang/OTP

Erlang/OTP is patching three branches in lockstep — 29 as current, 28 and 27 as maintenance — with each fix set published as a trio within minutes of itself. The window is dominated by security work in the network-facing applications: OTP 29.0.4 carried six CVEs including an epmd denial-of-service mitigation, and the 4 August trio brought SSH into line with RFC 4253 by rejecting packets not aligned to the cipher block size, with a timing-safe packet-discard path for CBC ciphers. A regression in the previous patch that stopped epmd binding to localhost was fixed in the same trio.

The maintenance pattern is unusually strict: 27, 28 and 29 receive the same trouble reports on the same day, so the effective support window is wide and sites on older majors are not being pushed forward by security pressure. Where the fixes land is consistent — ssh, ssl, crypto, public_key and erts account for nearly every changed application across these releases, which is the distribution epmd and the TLS/SSH stack impose on a distributed runtime. The CBC timing mitigation in particular is an old class of attack being closed properly rather than papered over.

Expect the next patch trio to follow the same shape — a small set of trouble reports applied to all three branches simultaneously — with ssh and ssl the most likely applications to change. Nothing in these entries indicates feature work landing on the patch branches; that stays on the next major.