In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7925: ensure tx headroom in usb_sdio_tx_prepare_skb
mt7925_usb_sdio_tx_prepare_skb() pushes a TX descriptor and a USB
header onto every skb and assumes the headroom for them is already
there. That holds for locally generated traffic, where mac80211
reserves hw->extra_tx_headroom, but forwarded frames are sent through
ieee80211_8023_xmit(), which does not reserve it. Bridge a wired
interface to an mt7925u AP and the first forwarded frame that arrives
short panics the kernel:
skbuff: skb_under_panic: len:415 put:4 tail:0x19b end:0x640 dev:wlan1
kernel BUG at net/core/skbuff.c:212!
Call trace:
skb_panic+0x58/0x60 (P)
skb_push+0x58/0x60
mt7925_usb_sdio_tx_prepare_skb+0xf8/0x1b8 [mt7925_common]
mt76u_tx_queue_skb+0xa0/0x1f8 [mt76_usb]
__mt76_tx_queue_skb+0x54/0xe8 [mt76]
mt76_txq_schedule.part.0+0x204/0x478 [mt76]
mt76_txq_schedule_all+0x50/0x80 [mt76]
mt792x_tx_worker+0x68/0x100 [mt792x_lib]
__mt76_worker_fn+0x84/0x150 [mt76]
Whether a given setup hits it depends on how much headroom the ingress
netdev leaves in its rx skbs. Reproduced on a Raspberry Pi 5 bridging
onboard ethernet to a Netgear A9000; originally reported on an MT7986
router running OpenWrt. Nick Morrow's testing on a Pi 4 (bcmgenet),
which leaves more headroom, helped narrow the trigger to the ingress
path.
The same bug was fixed on mt7921 by commit 98c4d0abf5c4 ("mt76:
mt7921: don't assume adequate headroom for SDIO headers"), but mt7925
was copied from mt7921 without the fix. Add the same guard here.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
- EG Severity
- Not assessed: no CVSS publishedA missing CVSS is not a severity of zero.
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). 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
- No SSVC decision: EchelonGraph has not assessed this CVECISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the BOD 26-04 block below.
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” 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