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            "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** (3 subsections)\n- **Incompatible Changes**\n- **Modules and Pragmata** (1 subsections)\n- **Platform Support** (1 subsections)\n- **Selected Bug Fixes**\n- **Acknowledgements**\n- **Reporting Bugs**\n- **Give Thanks**\n- **SEE ALSO**\n\nUse structuredContent.sections for detailed options, examples, and full documentation.\n"
        }
    ],
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        "mode": "man",
        "summary": "perl5261delta - what is new for perl v5.26.1",
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        "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,
                "subsections": []
            },
            {
                "name": "Modules and Pragmata",
                "lines": 1,
                "subsections": [
                    {
                        "name": "Updated Modules and Pragmata",
                        "lines": 10
                    }
                ]
            },
            {
                "name": "Platform Support",
                "lines": 1,
                "subsections": [
                    {
                        "name": "Platform-Specific Notes",
                        "lines": 14
                    }
                ]
            },
            {
                "name": "Selected Bug Fixes",
                "lines": 42,
                "subsections": []
            },
            {
                "name": "Acknowledgements",
                "lines": 25,
                "subsections": []
            },
            {
                "name": "Reporting Bugs",
                "lines": 13,
                "subsections": []
            },
            {
                "name": "Give Thanks",
                "lines": 7,
                "subsections": []
            },
            {
                "name": "SEE ALSO",
                "lines": 9,
                "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<https://github.com/Perl/perl5/issues/16021>\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] <https://github.com/Perl/perl5/issues/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<https://github.com/Perl/perl5/issues/16051>\n"
                    }
                ]
            },
            "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",
                "subsections": []
            },
            "Modules and Pragmata": {
                "content": "",
                "subsections": [
                    {
                        "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"
                    }
                ]
            },
            "Platform Support": {
                "content": "",
                "subsections": [
                    {
                        "name": "Platform-Specific Notes",
                        "content": "FreeBSD\n•   Building    with    g++    on    FreeBSD-11.0    has   been   fixed.    [GH   #15984]\n<https://github.com/Perl/perl5/issues/15984>\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<https://github.com/Perl/perl5/issues/16074>              [cpan              #121683]\n<https://rt.cpan.org/Public/Bug/Display.html?id=121683>        [cpan         #122353]\n<https://rt.cpan.org/Public/Bug/Display.html?id=122353>\n"
                    }
                ]
            },
            "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] <https://github.com/Perl/perl5/issues/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<https://github.com/Perl/perl5/issues/16029>\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<https://github.com/Perl/perl5/issues/16017>\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] <https://rt.perl.org/Public/Bug/Display.html?id=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] <https://github.com/Perl/perl5/issues/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<https://github.com/Perl/perl5/issues/16002>\n\n•   Occasional  \"Malformed UTF-8 character\" crashes in \"s//\" on utf8 strings have been fixed.\n[GH #16019] <https://github.com/Perl/perl5/issues/16019>\n\n•   \"perldoc       -f       s\"       now       finds       \"s///\".         [GH        #15989]\n<https://github.com/Perl/perl5/issues/15989>\n\n•   Some   erroneous   warnings   after   utf8  conversion  have  been  fixed.   [GH  #15958]\n<https://github.com/Perl/perl5/issues/15958>\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] <https://github.com/Perl/perl5/issues/11804>\n\n•   Spurious  \"Assuming  NOT  a  POSIX  class\"  warnings  have  been  removed.   [GH  #16001]\n<https://github.com/Perl/perl5/issues/16001>\n",
                "subsections": []
            },
            "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": []
            },
            "Reporting Bugs": {
                "content": "If  you  find  what  you  think  is  a  bug,  you  might  check  the  perl  bug  database  at\n<https://rt.perl.org/>  .  There may also be information at <http://www.perl.org/> , 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",
                "subsections": []
            },
            "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",
                "subsections": []
            },
            "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\nperl v5.38.2                                 2026-06-12                             PERL5261DELTA(1)",
                "subsections": []
            }
        }
    }
}