{ "content": [ { "type": "text", "text": "# perl5261delta (man)\n\n## NAME\n\nperl5261delta - what is new for perl v5.26.1\n\n## DESCRIPTION\n\nThis document describes differences between the 5.26.0 release and the 5.26.1 release.\n\n## Sections\n\n- **NAME**\n- **DESCRIPTION**\n- **Security** (9 subsections)\n- **Acknowledgements** (2 subsections)\n- **SEE ALSO**\n\nUse structuredContent.sections for detailed options, examples, and full documentation.\n" } ], "structuredContent": { "command": "perl5261delta", "section": "", "mode": "man", "summary": "perl5261delta - what is new for perl v5.26.1", "synopsis": null, "tldr_summary": null, "tldr_examples": [], "tldr_source": null, "flags": [], "examples": [], "see_also": [], "section_outline": [ { "name": "NAME", "lines": 2, "subsections": [] }, { "name": "DESCRIPTION", "lines": 5, "subsections": [] }, { "name": "Security", "lines": 1, "subsections": [ { "name": "[CVE-2017-12837] Heap buffer overflow in regular expression compiler", "lines": 4 }, { "name": "[CVE-2017-12883] Buffer over-read in regular expression parser", "lines": 4 }, { "name": "[CVE-2017-12814] $ENV{$key} stack buffer overflow on Windows", "lines": 4 }, { "name": "Incompatible Changes", "lines": 3 }, { "name": "Modules and Pragmata", "lines": 1 }, { "name": "Updated Modules and Pragmata", "lines": 10 }, { "name": "Platform Support", "lines": 1 }, { "name": "Platform-Specific Notes", "lines": 14 }, { "name": "Selected Bug Fixes", "lines": 42 } ] }, { "name": "Acknowledgements", "lines": 25, "subsections": [ { "name": "Reporting Bugs", "lines": 13 }, { "name": "Give Thanks", "lines": 7 } ] }, { "name": "SEE ALSO", "lines": 11, "subsections": [] } ], "sections": { "NAME": { "content": "perl5261delta - what is new for perl v5.26.1\n", "subsections": [] }, "DESCRIPTION": { "content": "This document describes differences between the 5.26.0 release and the 5.26.1 release.\n\nIf you are upgrading from an earlier release such as 5.24.0, first read perl5260delta, which\ndescribes differences between 5.24.0 and 5.26.0.\n", "subsections": [] }, "Security": { "content": "", "subsections": [ { "name": "[CVE-2017-12837] Heap buffer overflow in regular expression compiler", "content": "Compiling certain regular expression patterns with the case-insensitive modifier could cause\na heap buffer overflow and crash perl. This has now been fixed. [GH #16021]\n\n" }, { "name": "[CVE-2017-12883] Buffer over-read in regular expression parser", "content": "For certain types of syntax error in a regular expression pattern, the error message could\neither contain the contents of a random, possibly large, chunk of memory, or could crash\nperl. This has now been fixed. [GH #16025] \n" }, { "name": "[CVE-2017-12814] $ENV{$key} stack buffer overflow on Windows", "content": "A possible stack buffer overflow in the %ENV code on Windows has been fixed by removing the\nbuffer completely since it was superfluous anyway. [GH #16051]\n\n" }, { "name": "Incompatible Changes", "content": "There are no changes intentionally incompatible with 5.26.0. If any exist, they are bugs,\nand we request that you submit a report. See \"Reporting Bugs\" below.\n" }, { "name": "Modules and Pragmata", "content": "" }, { "name": "Updated Modules and Pragmata", "content": "• base has been upgraded from version 2.25 to 2.26.\n\nThe effects of dotless @INC on this module have been limited by the introduction of a\nmore refined and accurate solution for removing '.' from @INC while reducing the false\npositives.\n\n• charnames has been upgraded from version 1.44 to 1.45.\n\n• Module::CoreList has been upgraded from version 5.20170530 to 5.2017092226.\n" }, { "name": "Platform Support", "content": "" }, { "name": "Platform-Specific Notes", "content": "FreeBSD\n• Building with g++ on FreeBSD-11.0 has been fixed. [GH #15984]\n\n\nWindows\n• Support for compiling perl on Windows using Microsoft Visual Studio 2017 (containing\nVisual C++ 14.1) has been added.\n\n• Building XS modules with GCC 6 in a 64-bit build of Perl failed due to incorrect\nmapping of \"strtoll\" and \"strtoull\". This has now been fixed. [GH #16074]\n [cpan #121683]\n [cpan #122353]\n\n" }, { "name": "Selected Bug Fixes", "content": "• Several built-in functions previously had bugs that could cause them to write to the\ninternal stack without allocating room for the item being written. In rare situations,\nthis could have led to a crash. These bugs have now been fixed, and if any similar bugs\nare introduced in future, they will be detected automatically in debugging builds. [GH\n#16076] \n\n• Using a symbolic ref with postderef syntax as the key in a hash lookup was yielding an\nassertion failure on debugging builds. [GH #16029]\n\n\n• List assignment (\"aassign\") could in some rare cases allocate an entry on the mortal\nstack and leave the entry uninitialized. [GH #16017]\n\n\n• Attempting to apply an attribute to an \"our\" variable where a function of that name\nalready exists could result in a NULL pointer being supplied where an SV was expected,\ncrashing perl. [perl #131597] \n\n• The code that vivifies a typeglob out of a code ref made some false assumptions that\ncould lead to a crash in cases such as $::{\"A\"} = sub {}; \\&{\"A\"}. This has now been\nfixed. [GH #15937] \n\n• \"myatof2\" no longer reads beyond the terminating NUL, which previously occurred if the\ndecimal point is immediately before the NUL. [GH #16002]\n\n\n• Occasional \"Malformed UTF-8 character\" crashes in \"s//\" on utf8 strings have been fixed.\n[GH #16019] \n\n• \"perldoc -f s\" now finds \"s///\". [GH #15989]\n\n\n• Some erroneous warnings after utf8 conversion have been fixed. [GH #15958]\n\n\n• The \"jmpenv\" frame to catch Perl exceptions is set up lazily, and this used to be a bit\ntoo lazy. The catcher is now set up earlier, preventing some possible crashes. [GH\n#11804] \n\n• Spurious \"Assuming NOT a POSIX class\" warnings have been removed. [GH #16001]\n\n" } ] }, "Acknowledgements": { "content": "Perl 5.26.1 represents approximately 4 months of development since Perl 5.26.0 and contains\napproximately 8,900 lines of changes across 85 files from 23 authors.\n\nExcluding auto-generated files, documentation and release tools, there were approximately 990\nlines of changes to 38 .pm, .t, .c and .h files.\n\nPerl continues to flourish into its third decade thanks to a vibrant community of users and\ndevelopers. The following people are known to have contributed the improvements that became\nPerl 5.26.1:\n\nAaron Crane, Andy Dougherty, Aristotle Pagaltzis, Chris 'BinGOs' Williams, Craig A. Berry,\nDagfinn Ilmari Mannsåker, David Mitchell, E. Choroba, Eric Herman, Father Chrysostomos,\nJacques Germishuys, James E Keenan, John SJ Anderson, Karl Williamson, Ken Brown, Lukas Mai,\nMatthew Horsfall, Ricardo Signes, Sawyer X, Steve Hay, Tony Cook, Yves Orton, Zefram.\n\nThe list above is almost certainly incomplete as it is automatically generated from version\ncontrol history. In particular, it does not include the names of the (very much appreciated)\ncontributors who reported issues to the Perl bug tracker.\n\nMany of the changes included in this version originated in the CPAN modules included in\nPerl's core. We're grateful to the entire CPAN community for helping Perl to flourish.\n\nFor a more complete list of all of Perl's historical contributors, please see the AUTHORS\nfile in the Perl source distribution.\n", "subsections": [ { "name": "Reporting Bugs", "content": "If you find what you think is a bug, you might check the perl bug database at\n . There may also be information at , the Perl\nHome Page.\n\nIf you believe you have an unreported bug, please run the perlbug program included with your\nrelease. Be sure to trim your bug down to a tiny but sufficient test case. Your bug report,\nalong with the output of \"perl -V\", will be sent off to perlbug@perl.org to be analysed by\nthe Perl porting team.\n\nIf the bug you are reporting has security implications which make it inappropriate to send to\na publicly archived mailing list, then see \"SECURITY VULNERABILITY CONTACT INFORMATION\" in\nperlsec for details of how to report the issue.\n" }, { "name": "Give Thanks", "content": "If you wish to thank the Perl 5 Porters for the work we had done in Perl 5, you can do so by\nrunning the \"perlthanks\" program:\n\nperlthanks\n\nThis will send an email to the Perl 5 Porters list with your show of thanks.\n" } ] }, "SEE ALSO": { "content": "The Changes file for an explanation of how to view exhaustive details on what changed.\n\nThe INSTALL file for how to build Perl.\n\nThe README file for general stuff.\n\nThe Artistic and Copying files for copyright information.\n\n\n\nperl v5.34.0 2025-07-25 PERL5261DELTA(1)", "subsections": [] } } } }