1Bitcoin Core version 0.11.1 is now available from:
2
3  <https://bitcoin.org/bin/bitcoin-core-0.11.1/>
4
5This is a new minor version release, bringing security fixes. It is recommended
6to upgrade to this version as soon as possible.
7
8Please report bugs using the issue tracker at github:
9
10  <https://github.com/bitcoin/bitcoin/issues>
11
12Upgrading and downgrading
13=========================
14
15How to Upgrade
16--------------
17
18If you are running an older version, shut it down. Wait until it has completely
19shut down (which might take a few minutes for older versions), then run the
20installer (on Windows) or just copy over /Applications/Bitcoin-Qt (on Mac) or
21bitcoind/bitcoin-qt (on Linux).
22
23Downgrade warning
24------------------
25
26Because release 0.10.0 and later makes use of headers-first synchronization and
27parallel block download (see further), the block files and databases are not
28backwards-compatible with pre-0.10 versions of Bitcoin Core or other software:
29
30* Blocks will be stored on disk out of order (in the order they are
31received, really), which makes it incompatible with some tools or
32other programs. Reindexing using earlier versions will also not work
33anymore as a result of this.
34
35* The block index database will now hold headers for which no block is
36stored on disk, which earlier versions won't support.
37
38If you want to be able to downgrade smoothly, make a backup of your entire data
39directory. Without this your node will need start syncing (or importing from
40bootstrap.dat) anew afterwards. It is possible that the data from a completely
41synchronised 0.10 node may be usable in older versions as-is, but this is not
42supported and may break as soon as the older version attempts to reindex.
43
44This does not affect wallet forward or backward compatibility. There are no
45known problems when downgrading from 0.11.x to 0.10.x.
46
47Notable changes
48===============
49
50Fix buffer overflow in bundled upnp
51------------------------------------
52
53Bundled miniupnpc was updated to 1.9.20151008. This fixes a buffer overflow in
54the XML parser during initial network discovery.
55
56Details can be found here: http://talosintel.com/reports/TALOS-2015-0035/
57
58This applies to the distributed executables only, not when building from source or
59using distribution provided packages.
60
61Additionally, upnp has been disabled by default. This may result in a lower
62number of reachable nodes on IPv4, however this prevents future libupnpc
63vulnerabilities from being a structural risk to the network
64(see https://github.com/bitcoin/bitcoin/pull/6795).
65
66Test for LowS signatures before relaying
67-----------------------------------------
68
69Make the node require the canonical 'low-s' encoding for ECDSA signatures when
70relaying or mining.  This removes a nuisance malleability vector.
71
72Consensus behavior is unchanged.
73
74If widely deployed this change would eliminate the last remaining known vector
75for nuisance malleability on SIGHASH_ALL P2PKH transactions. On the down-side
76it will block most transactions made by sufficiently out of date software.
77
78Unlike the other avenues to change txids on transactions this
79one was randomly violated by all deployed bitcoin software prior to
80its discovery. So, while other malleability vectors where made
81non-standard as soon as they were discovered, this one has remained
82permitted. Even BIP62 did not propose applying this rule to
83old version transactions, but conforming implementations have become
84much more common since BIP62 was initially written.
85
86Bitcoin Core has produced compatible signatures since a28fb70e in
87September 2013, but this didn't make it into a release until 0.9
88in March 2014; Bitcoinj has done so for a similar span of time.
89Bitcoinjs and electrum have been more recently updated.
90
91This does not replace the need for BIP62 or similar, as miners can
92still cooperate to break transactions.  Nor does it replace the
93need for wallet software to handle malleability sanely[1]. This
94only eliminates the cheap and irritating DOS attack.
95
96[1] On the Malleability of Bitcoin Transactions
97Marcin Andrychowicz, Stefan Dziembowski, Daniel Malinowski, Łukasz Mazurek
98http://fc15.ifca.ai/preproceedings/bitcoin/paper_9.pdf
99
100Minimum relay fee default increase
101-----------------------------------
102
103The default for the `-minrelaytxfee` setting has been increased from `0.00001`
104to `0.00005`.
105
106This is necessitated by the current transaction flooding, causing
107outrageous memory usage on nodes due to the mempool ballooning. This is a
108temporary measure, bridging the time until a dynamic method for determining
109this fee is merged (which will be in 0.12).
110
111(see https://github.com/bitcoin/bitcoin/pull/6793, as well as the 0.11
112release notes, in which this value was suggested)
113
1140.11.1 Change log
115=================
116
117Detailed release notes follow. This overview includes changes that affect
118behavior, not code moves, refactors and string updates. For convenience in locating
119the code changes and accompanying discussion, both the pull request and
120git merge commit are mentioned.
121
122- #6438 `2531438` openssl: avoid config file load/race
123- #6439 `980f820` Updated URL location of netinstall for Debian
124- #6384 `8e5a969` qt: Force TLS1.0+ for SSL connections
125- #6471 `92401c2` Depends: bump to qt 5.5
126- #6224 `93b606a` Be even stricter in processing unrequested blocks
127- #6571 `100ac4e` libbitcoinconsensus: avoid a crash in multi-threaded environments
128- #6545 `649f5d9` Do not store more than 200 timedata samples.
129- #6694 `834e299` [QT] fix thin space word wrap line break issue
130- #6703 `1cd7952` Backport bugfixes to 0.11
131- #6750 `5ed8d0b` Recent rejects backport to v0.11
132- #6769 `71cc9d9` Test LowS in standardness, removes nuisance malleability vector.
133- #6789 `b4ad73f` Update miniupnpc to 1.9.20151008
134- #6785 `b4dc33e` Backport to v0.11: In (strCommand == "tx"), return if AlreadyHave()
135- #6412 `0095b9a` Test whether created sockets are select()able
136- #6795 `4dbcec0` net: Disable upnp by default
137- #6793 `e7bcc4a` Bump minrelaytxfee default
138
139Credits
140=======
141
142Thanks to everyone who directly contributed to this release:
143
144- Adam Weiss
145- Alex Morcos
146- Casey Rodarmor
147- Cory Fields
148- fanquake
149- Gregory Maxwell
150- Jonas Schnelli
151- J Ross Nicoll
152- Luke Dashjr
153- Pavel Janík
154- Pavel Vasin
155- Peter Todd
156- Pieter Wuille
157- randy-waterhouse
158- Ross Nicoll
159- Suhas Daftuar
160- tailsjoin
161- ฿tcDrak
162- Tom Harding
163- Veres Lajos
164- Wladimir J. van der Laan
165
166And those who contributed additional code review and/or security research:
167
168- timothy on IRC for reporting the issue
169- Vulnerability in miniupnp discovered by Aleksandar Nikolic of Cisco Talos
170
171As well as everyone that helped translating on [Transifex](https://www.transifex.com/projects/p/bitcoin/).
172
173