In the Linux kernel, the following vulnerability has been resolved:
vrf: revert "vrf: Remove unnecessary RCU-bh critical section"
This reverts commit 504fc6f4f7f681d2a03aa5f68aad549d90eab853.
dev_queue_xmit_nit is expected to be called with BH disabled.
__dev_queue_xmit has the following:
/* Disable soft irqs for various locks below. Also
* stops preemption for RCU.
*/
rcu_read_lock_bh();
VRF must follow this invariant. The referenced commit removed this
protection. Which triggered a lockdep warning:
================================
WARNING: inconsistent lock state
6.11.0 #1 Tainted: G W
--------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
btserver/134819 [HC0[0]:SC0[0]:HE1:SE1] takes:
ffff8882da30c118 (rlock-AF_PACKET){+.?.}-{2:2}, at: tpacket_rcv+0x863/0x3b30
{IN-SOFTIRQ-W} state was registered at:
lock_acquire+0x19a/0x4f0
_raw_spin_lock+0x27/0x40
packet_rcv+0xa33/0x1320
__netif_receive_skb_core.constprop.0+0xcb0/0x3a90
__netif_receive_skb_list_core+0x2c9/0x890
netif_receive_skb_list_internal+0x610/0xcc0
[...]
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rlock-AF_PACKET);
lock(rlock-AF_PACKET);
* DEADLOCK *
Call Trace:
dump_stack_lvl+0x73/0xa0
mark_lock+0x102e/0x16b0
__lock_acquire+0x9ae/0x6170
lock_acquire+0x19a/0x4f0
_raw_spin_lock+0x27/0x40
tpacket_rcv+0x863/0x3b30
dev_queue_xmit_nit+0x709/0xa40
vrf_finish_direct+0x26e/0x340 [vrf]
vrf_l3_out+0x5f4/0xe80 [vrf]
__ip_local_out+0x51e/0x7a0
[...]
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-25). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it