Backtrace:

#0  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44
        tid = <optimized out>
        ret = 0
        pd = <optimized out>
        old_mask = {__val = {140639726716624}}
        ret = <optimized out>
#1  0x00007fe95c278b93 in __pthread_kill_internal (threadid=<optimized out>, signo=6) at pthread_kill.c:89
No locals.
#2  0x00007fe95c21cf4e in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
        ret = <optimized out>
#3  0x00007fe95c20443f in __GI_abort () at abort.c:77
        act = {__sigaction_handler = {sa_handler = 0xb, sa_sigaction = 0xb}, sa_mask = {__val = {11432429142575510272, 0, 246699096902, 140639726716848, 140640258482674, 140639726716832, 11432429142575510272, 0, 246699172912, 140639646736592, 11432429142575510272, 0, 11432429142575510272, 140639726716848, 140640250737647, 140639646736592}}, sa_flags = 1022609440, sa_restorer = 0x1000}
#4  0x00007fe95c205490 in __libc_message_impl (vma_name=vma_name@entry=0x7fe95c1cb2f6 "glibc: fatal", fmt=fmt@entry=0x7fe95c1ce7c6 "*** %s ***: terminated\n") at ../sysdeps/posix/libc_fatal.c:138
        ap = {{gp_offset = 24, fp_offset = 32745, overflow_arg_area = 0x7fe93cf3c960, reg_save_area = 0x7fe93cf3c8f0}}
        fd = 2
        iov = {{iov_base = 0x7fe95c1ce7c6, iov_len = 4}, {iov_base = 0x7fe95c1ce7de, iov_len = 23}, {iov_base = 0x7fe95c1ce7cc, iov_len = 17}, {iov_base = 0x1530, iov_len = 9696}, {iov_base = 0x7fe93cf3c860, iov_len = 140640250246824}, {iov_base = 0x7fe93cf3c870, iov_len = 140640250246824}, {iov_base = 0x310, iov_len = 80}, {iov_base = 0x7fe93cf3c8a0, iov_len = 140640250251278}, {iov_base = 0x7fe93cf3c8a0, iov_len = 140640250246824}, {iov_base = 0x130, iov_len = 140639777862320}, {iov_base = 0x18, iov_len = 0}, {iov_base = 0x7fe93cf3c8d0, iov_len = 140640250251527}, {iov_base = 0x130, iov_len = 140639649626128}, {iov_base = 0x7fe93cf3c8f0, iov_len = 140639643631664}, {iov_base = 0x7fe93cf3c900, iov_len = 140639984880926}}
        iovcnt = <optimized out>
        total = <optimized out>
        cp = <optimized out>
#5  0x00007fe95c3063f0 in __libc_message_wrapper (vmaname=0x7fe95c1cb2f6 "glibc: fatal", fmt=0x7fe95c1ce7c6 "*** %s ***: terminated\n") at ../include/stdio.h:203
No locals.
#6  __GI___fortify_fail (msg=msg@entry=0x7fe95c1ce7de "stack smashing detected") at fortify_fail.c:24
No locals.
#7  0x00007fe95c3077a4 in __stack_chk_fail () at stack_chk_fail.c:24
No locals.
#8  0x00007fe94c7fa438 in dnf5_transaction_thread (job=0x55bd2d0730d0, params=<optimized out>, user_data=<optimized out>) at ../backends/dnf5/dnf5-backend-thread.cpp:571
        backend = <optimized out>
        priv = 0x55bd2c717340
        role = <optimized out>
        locker = <optimized out>
#9  0x000055bd070bdb12 in pk_backend_job_thread_setup (thread_data=0x55bd2c9031b0) at ../src/pk-backend-job.c:785
        helper = 0x55bd2c9031b0
#10 0x00007fe95ca2f5e2 in g_thread_proxy (data=0x7fe940000cd0) at ../glib/gthread.c:897
        thread = 0x7fe940000cd0
        __func__ = "g_thread_proxy"
#11 0x00007fe95c276a39 in start_thread (arg=<optimized out>) at pthread_create.c:454
        ret = <optimized out>
        pd = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {-768, -7445941592931667755, 33, 140735186763856, 2, 140735186764119, -7445941592963125035, -7446013435724795691}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
        prevstate = <optimized out>
#12 0x00007fe95c2faa1c in __GI___clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:78
No locals.

I confirm the issue, forwarded upstream https://github.com/rpm-software-management/dnf5/issues/2869.

This update has been unpushed.

Thanks for the thorough investigation and fix.