Cannot update Firefox snap

snap
1

Hi, I have looked but have not found a similar error.

Using Kubuntu questing when attempting to update the Firefox snap, (refresh of version 147.04-1) I get the following error.

cannot perform the following tasks:

  • Run post-refresh hook of “firefox” snap if present (run hook “post-refresh”:

snap-confine is packaged without necessary permissions and cannot continue required permitted capability cap_fowner not found in current capabilities: cap_chown,cap_dac_override,cap_dac_read_search,cap_setgid,cap_setuid,cap_sys_chroot,cap_sys_ptrace,cap_sys_admin,cap_sys_resource,cap_bpf=ep -----)

Linux 6.17.0-14-generic #14-Ubuntu SMP PREEMPT_DYNAMIC Fri Jan  9 17:01:16 UTC 2026 x86_64 GNU/Linux

Seems to point to missing cap_fowner. How is this permission granted, and how do I fix it?

{Update}

This error is produced on multiple snap programs, when I run from terminal any program installed by snap i get the same error. (powershell, puddletag-snap, launcher-ot-minecraft)

:~$ powershell
snap-confine is packaged without necessary permissions and cannot continue
required permitted capability cap_fowner not found in current capabilities:
  cap_wake_alarm=i cap_chown,cap_dac_override,cap_dac_read_search,cap_setgid,cap_setuid,cap_sys_chroot,cap_sys_ptrace,cap_sys_admin+p
2

Try running the following command in a terminal to reset the capability settings of the snap-confine program:

setcap -q - /usr/lib/snapd/snap-confine < /usr/lib/snapd/snap-confine.caps
3

Thank you Lin-Buo-Re for this, here is the output, but it did not fix the issue. I tried to restart snap, results below.

:~$ sudo setcap -v - /usr/lib/snapd/snap-confine < /usr/lib/snapd/snap-confine.caps Please enter caps for file [empty line to end]: /usr/lib/snapd/snap-confine: OK

Below is the content of file snap-confine.caps

cap_chown,cap_dac_override,cap_dac_read_search,cap_fowner,cap_setgid,cap_setuid,cap_sys_chroot,cap_sys_ptrace,cap_sys_admin=p

jason:~$ snap refresh
error: cannot perform the following tasks:
- Run post-refresh hook of "firefox" snap if present (run hook "post-refresh": 
-----
snap-confine is packaged without necessary permissions and cannot continue
required permitted capability cap_fowner not found in current capabilities:
  cap_chown,cap_dac_override,cap_dac_read_search,cap_setgid,cap_setuid,cap_sys_chroot,cap_sys_ptrace,cap_sys_admin,cap_sys_resource,cap_bpf=ep
-----)
jason:~$ sudo systemctl restart snapd snapd.socket
[sudo: authenticate] Password: 
jason:~$ sudo systemctl daemon-reload
jason:~$ snap refresh
error: cannot perform the following tasks:
- Run post-refresh hook of "firefox" snap if present (run hook "post-refresh": 
-----
snap-confine is packaged without necessary permissions and cannot continue
required permitted capability cap_fowner not found in current capabilities:
  cap_chown,cap_dac_override,cap_dac_read_search,cap_setgid,cap_setuid,cap_sys_chroot,cap_sys_ptrace,cap_sys_admin,cap_sys_resource,cap_bpf=ep
-----)
jason:~$ sudo snap debug state /var/lib/snapd/state.json
ID   Status  Spawn               Ready               Label         Summary
620  Error   today at 05:26 CDT  today at 05:26 CDT  auto-refresh  Auto-refresh snap "firefox"
621  Error   today at 06:09 CDT  today at 06:09 CDT  refresh-snap  Refresh "firefox" snap from "latest/stable" channel
622  Error   today at 20:25 CDT  today at 20:25 CDT  refresh-snap  Refresh "firefox" snap from "latest/stable" channel
623  Error   today at 20:48 CDT  today at 20:48 CDT  refresh-snap  Refresh "firefox" snap
624  Error   today at 20:53 CDT  today at 20:53 CDT  refresh-snap  Refresh "firefox" snap
jason:~$ sudo snap version
snap          2.73+ubuntu25.10
snapd         2.73+ubuntu25.10
series        16
ubuntu        25.10
kernel        6.17.0-14-generic
architecture  amd64
jason:~$
4

You did not run the command correctly, please copy and paste the entire code block into the terminal instead.

5

Lin-Buo-Ren,

Here is the result of the code copied from your initial post.

:~$ setcap -q - /usr/lib/snapd/snap-confine < /usr/lib/snapd/snap-confine.caps
unable to set CAP_SETFCAP effective capability: Operation not permitted
:~$ sudo setcap -q - /usr/lib/snapd/snap-confine < /usr/lib/snapd/snap-confine.caps
[sudo: authenticate] Password: 
:~$ snap refresh
error: cannot perform the following tasks:
- Run post-refresh hook of "firefox" snap if present (run hook "post-refresh": 
-----
snap-confine is packaged without necessary permissions and cannot continue
required permitted capability cap_fowner not found in current capabilities:
  cap_chown,cap_dac_override,cap_dac_read_search,cap_setgid,cap_setuid,cap_sys_chroot,cap_sys_ptrace,cap_sys_admin,cap_sys_resource,cap_bpf=ep
-----)
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6

This explains why you might be seeing missing capabilities. Try reinstalling snapd “deb” pkg so it matches snap version, it should regenerate the policy with correct flags.

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