[glibc] Document CVE-2026-5358 and CVE-2026-5928

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=da3863e62e8ff1abc6b92cfe6d899ca3e80c8c4b

commit da3863e62e8ff1abc6b92cfe6d899ca3e80c8c4b
Author: Siddhesh Poyarekar <[email protected]>
Date:   Fri Apr 10 12:52:11 2026 -0400

    Document CVE-2026-5358 and CVE-2026-5928
    
    Signed-off-by: Siddhesh Poyarekar <[email protected]>

Diff:
---
 advisories/GLIBC-SA-2026-0008 | 16 ++++++++++++++++
 advisories/GLIBC-SA-2026-0010 | 24 ++++++++++++++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/advisories/GLIBC-SA-2026-0008 b/advisories/GLIBC-SA-2026-0008
new file mode 100644
index 0000000000..1dbd9808e0
--- /dev/null
+++ b/advisories/GLIBC-SA-2026-0008
@@ -0,0 +1,16 @@
+Static buffer overflow in deprecated nis_local_principal
+
+The obsolete nis_local_principal function in the GNU C Library version
+2.43 and older may overflow a buffer in the data section, which could
+allow an attacker to spoof a crafted response to a UDP request generated
+by this function and overwrite neighboring static data in the requesting
+application.
+
+NIS support is obsolete and has been deprecated in the GNU C Library
+since version 2.26 and is only maintained for legacy usage. Applications
+should port away from NIS to more modern identity and access management
+services.
+
+CVE-Id: CVE-2026-5358
+Public-Date: 2026-04-10
+Reported-by: Rahul Hoysala
diff --git a/advisories/GLIBC-SA-2026-0010 b/advisories/GLIBC-SA-2026-0010
new file mode 100644
index 0000000000..ae9953fb71
--- /dev/null
+++ b/advisories/GLIBC-SA-2026-0010
@@ -0,0 +1,24 @@
+Potential buffer under-read in ungetwc
+
+Calling the ungetwc function on a FILE stream with wide characters
+encoded in a character set that has overlaps between its single byte and
+multi-byte character encodings, in the GNU C Library version 2.43 or
+earlier, may result in an attempt to read bytes before an allocated
+buffer, potentially resulting in unintentional disclosure of neighboring
+data in the heap, or a program crash.
+
+A bug in the wide character pushback implementation
+(_IO_wdefault_pbackfail in libio/wgenops.c) causes ungetwc() to operate
+on the regular character buffer (fp->_IO_read_ptr) instead of the actual
+wide-stream read pointer (fp->_wide_data->_IO_read_ptr). The program
+crash may happen in cases where fp->_IO_read_ptr is not initialized and
+hence points to NULL. The buffer under-read requires a special situation
+where the input character encoding is such that there are overlaps
+between single byte representations and multibyte representations in
+that encoding, resulting in spurious matches.  The spurious match case
+is not possible in the standard Unicode character sets.
+
+CVE-Id: CVE-2026-5928
+Public-Date: 2026-03-17
+Reported-by: Rocket Ma
+Vulnerable-Commit: d64b6ad07585b8a37e5fecc9a47fcee766d52ede (2.1.1-89)