This is the OpenBSD 2.6 release errata & patch list:

All architectures

• 023: SECURITY FIX: May 25, 2000
  A misuse of ipf(8) keep-state rules can result in firewall rules being bypassed. This patch also includes fixes for an unaligned timestamp issue, and reliability fixes for ipmon and the in-kernel ftp proxy.
  A jumbo patch exists, which remedies this problem, and updates ipf to version 3.3.16.

• 022: SECURITY FIX: May 25, 2000
  xlockmore has a localhost attack against it which allows recovery of the encrypted hash of the root password. The damage to systems using DES passwords from this attack is pretty heavy, but to systems with a well-chosen root password under blowfish encoding (see crypt(3)) the impact is much reduced.
  (Aside: We do not consider this a localhost root hole in the default install, since we have not seen a fast blowfish cracker yet ;-)
  A source code patch exists, which remedies this problem. This is the 2nd patch designed to solve this problem.

• 021: RZSZ SNOOPING: Jan 31, 2000
  The rzsz port was removed from the ports collection, as it collects and sends user information to a designated email address, effectively spying on you. It is recommended that you remove this package if you installed it.

• 020: LIBRARY IMPROVEMENT: Jan 26, 2000
  syslog(3) would not try to reopen the socket, thus, nightly newsyslog(8) would cause syslogd(8) to not see new messages. A source code patch exists, which remedies this problem.

• 019: DRIVER IMPROVEMENT: Jan 20, 2000
  Intel fxp cards with National Semiconductor PHYs (nsphy) have trouble negotiating and maintaining 100Mb link integrity.
  A source code patch exists, which remedies this problem.

• 018: SECURITY FIX: Jan 20, 2000
  Systems running with procfs enabled and mounted are vulnerable to having the stderr output of setuid processes directed onto a pre-seeked descriptor onto the stack in their own procfs memory.
  Note that procfs is not mounted by default in OpenBSD.
  A source code patch exists, which remedies this problem.

• 015: Y2K FIX: Jan 9, 2000
  The at(1) command was unable to parse some kinds of dates.
  A source code patch exists, which remedies this problem.

• 013: Y2K FIX: Jan 3, 2000
  A minor problem in the logging support for the adduser(8) command.
  A source code patch exists, which remedies this problem.

• 012: DRIVER IMPROVEMENT: Jan 3, 2000
  The 3C900B-TPO fails to select the correct media type (it never sees or sends packets).
  A source code patch exists, which remedies this problem.

• 011: SECURITY FIX: Dec 4, 1999
  Various bugs in poll(2) may cause a kernel crash.
  A source code patch exists, which remedies this problem.

• 010: SECURITY FIX: Dec 4, 1999
  Sendmail had a race in aliases file handling, which this patch fixes.
  A source code patch exists, which remedies this problem.

• 009: DRIVER IMPROVEMENTS: Dec 4, 1999
  Various improvements have been made to the IDE/ATAPI subsystem since the 2.6 release shipped.
  Some of these improvements make some recalcitrant devices work much better.
  Revision 1 of this jumbo source code patch exists.
  

• 016: SECURITY FIX: Dec 2, 1999
  A buffer overflow in the RSAREF code included in the USA version of the libssl package (called sslUSA, is possibly exploitable in isakmpd if SSL/RSA features are enabled or used.
  OpenSSH and httpd (with -DSSL) are not vulnerable.
  NOTE: International users using the ssl26 package are not affected.

  To check what package you are using, use

  # pkg_info sslUSA26
  

  The patched library says:
  "ssl26.1 USA-only non-commercial crypto libs incl. SSL & RSA"

  Non-commercial USA users who installed the ssl package before December 3 should upgrade their sslUSA26 package using:
  

  # pkg_delete sslUSA26
  # pkg_add -v sslUSA26.tar.gz
  

  Using the new sslUSA26.tar.gz files which have been placed on the FTP mirrors.
  For more information, see the advisory.
  NOTE: this problem turned out to not be unexploitable in OpenSSH.

• 017: FUNCTIONALITY ADDITION: Nov 14, 1999
  Fortran doesn't work right. The file /usr/include/g2c.h is missing in the release.
  A source code patch exists which remedies this problem.
  The patch fixes the source tree and describes how to properly add the include file to your system.

• 005: FUNCTIONALITY ADDITION: Nov 11, 1999
  Various OpenSSH improvements have been made since the 2.6 release shipped.
  To resolve the various (non-security related) features which users may want, we are making a jumbo patch available. This is now at VERSION FOUR.
  Revision 4 of this jumbo source code patch exists.
  NOTE: /etc/sshd_config and /etc/ssh_config may need changes.

• 003: FUNCTIONALITY FIX: Nov 10, 1999
  m4 is quite broken in the 2.6 release.
  The 3rd version of the source code patch exists, which remedies this problem.

• 002: SECURITY FIX: Nov 9, 1999
  Any user can change interface media configurations.
  A source code patch exists which remedies this problem.

• 001: RELIABILITY FIX: Nov 8, 1999
  A race condition in newsyslog(8) can cause errors in log file rotation.
  A source code patch exists which remedies this problem.

i386

• No problems identified yet.

mac68k

• 007: RELIABILITY FIX: Nov 12, 1999
  All m68k kernels can possibly be crashed by a user.
  A source code patch exists which remedies this problem.

sparc

• 014: Y2K FIX: Jan 3, 2000
  A minor problem; the sparc eeprom(8) command is not Y2K compliant.
  Revision 2 of the source code patch exists, which remedies this problem.

• 004: RELIABILITY FIX: Nov 12, 1999
  The sparc kernel can be crashed by a user.
  A source code patch exists which remedies this problem.

amiga

• 007: RELIABILITY FIX: Nov 12, 1999
  All m68k kernels can possibly be crashed by a user.
  A source code patch exists which remedies this problem.

pmax

• No problems identified yet.

arc

• No problems identified yet.

alpha

• 006: RELIABILITY FIX: Nov 13, 1999
  The alpha kernel can possibly be crashed by a user.
  A source code patch exists which remedies this problem.

hp300

• 007: RELIABILITY FIX: Nov 12, 1999
  All m68k kernels can possibly be crashed by a user.
  A source code patch exists which remedies this problem.

mvme68k

• 007: RELIABILITY FIX: Nov 12, 1999
  All m68k kernels can possibly be crashed by a user.
  A source code patch exists which remedies this problem.

powerpc

• No problems identified yet.