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Linux Kernel EUVDEUVD-2026-58915

| CVE-2026-72157 HIGH
2026-08-15 416baaa9-dc9f-4396-8d5f-8c081fb06d67 GHSA-8f5r-c72f-67g5
8.8
CVSS 3.1 · Vendor: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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Severity by source

Vendor (416baaa9-dc9f-4396-8d5f-8c081fb06d67) PRIMARY
8.8 HIGH
AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
vuln.today AI
8.8 HIGH

Adjacent vector because Thunderbolt requires physical proximity; no network-layer authentication for peer frames; kernel memory corruption yields full CIA impact on the host.

3.1 AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
4.0 AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
SUSE
8.1 HIGH
AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Red Hat
7.0 MEDIUM
qualitative

Primary rating from Vendor (416baaa9-dc9f-4396-8d5f-8c081fb06d67).

CVSS VectorVendor: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Attack Vector
Adjacent
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

5
Analysis Generated
Aug 17, 2026 - 07:19 vuln.today
CVSS changed
Aug 17, 2026 - 06:22 NVD
8.8 (HIGH)
Patch available
Aug 15, 2026 - 07:20 EUVD
CVE Published
Aug 15, 2026 - 06:21 cve.org
UNKNOWN (no severity yet)
CVE Published
Aug 15, 2026 - 06:21 cve.org
HIGH 8.8

DescriptionCVE.org

In the Linux kernel, the following vulnerability has been resolved:

net: thunderbolt: Fix frags[] overflow by bounding frame_count

tbnet_poll() assembles a multi-frame ThunderboltIP packet into one skb. The first frame goes into the skb linear area and every further frame is added as a page fragment.

skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, hdr_size, frame_size, TBNET_RX_PAGE_SIZE - hdr_size);

A packet of frame_count frames therefore ends up with frame_count - 1 fragments. tbnet_check_frame() only bounds the peer supplied frame_count to TBNET_RING_SIZE / 4 (64), which is far above MAX_SKB_FRAGS (17 by default). A peer that sends a packet of 19 or more small frames pushes nr_frags past MAX_SKB_FRAGS, so skb_add_rx_frag() writes past skb_shinfo()->frags[] and corrupts memory after the shared info.

Tighten the start of packet bound to MAX_SKB_FRAGS + 1 so a packet can never produce more fragments than frags[] can hold. This matches the recent skb frags overflow fixes in other receive paths, for example f0813bcd2d9d ("net: wwan: t7xx: fix potential skb->frags overflow in RX path") and 600dc40554dc ("net: usb: cdc-phonet: fix skb frags[] overflow in rx_complete()").

AnalysisAI

Memory corruption in the Linux kernel's ThunderboltIP receive path allows an adjacent unauthenticated attacker to overflow the skb frags[] array by sending a crafted multi-frame packet with 19 or more small frames. The insufficient frame_count bound in tbnet_check_frame() (capped at TBNET_RING_SIZE/4 = 64) far exceeds MAX_SKB_FRAGS (17), causing skb_add_rx_frag() to write past the frags[] array and corrupt kernel memory. EPSS is low (0.21%, 11th percentile), no public exploit exists, and CISA KEV confirmation is absent, but CVSS 8.8 reflects the severity of kernel memory corruption once Thunderbolt physical access is achieved.

Technical ContextAI

The vulnerability resides in drivers/net/thunderbolt.c, the ThunderboltIP networking subsystem of the Linux kernel, introduced at commit e69b6c02b4c3b8d03be7136f90dd9551ad5a5a5e in Linux 4.15. ThunderboltIP enables IP-layer networking between Thunderbolt-connected peers. The NAPI poll handler tbnet_poll() assembles multi-frame packets by placing the first frame in the skb linear area and appending each subsequent frame as a page fragment via skb_add_rx_frag(). The skb_shinfo()->frags[] array is statically sized at MAX_SKB_FRAGS (17 entries by default). The validation function tbnet_check_frame() permitted frame_count values up to TBNET_RING_SIZE/4 (64), which means a packet with 19 frames would produce 18 fragments - one past the array boundary - causing an out-of-bounds write (functionally CWE-787, though NVD lists CWE as N/A). This class of vulnerability is structurally identical to fixes applied to the wwan t7xx driver (f0813bcd2d9d) and USB CDC Phonet driver (600dc40554dc). The fix tightens the bound to MAX_SKB_FRAGS + 1.

RemediationAI

Upgrade to a patched Linux kernel version: 6.6.145, 6.12.97, 6.18.40, 7.1.5, or 7.2-rc1, per the upstream stable commits at https://git.kernel.org/stable/c/. Distribution users should apply vendor security updates as they become available for RHEL, Debian, Ubuntu, SUSE, and other supported kernel variants. If immediate kernel patching is not feasible, the primary compensating control is to unload or blacklist the thunderbolt module by adding blacklist thunderbolt to /etc/modprobe.d/blacklist.conf and running modprobe -r thunderbolt; this disables all Thunderbolt functionality including peripheral connectivity, which may be operationally disruptive. A less disruptive alternative is to enforce Thunderbolt security levels at the BIOS/UEFI or via the sysfs thunderbolt_security interface (e.g., setting security=user or security=secure) to require explicit device authorization before peer connections are established, reducing the attack surface without fully disabling Thunderbolt. Note that sysfs-based authorization controls reduce risk but do not patch the underlying frags[] overflow in the receive path.

Vendor StatusVendor

SUSE

Severity: Important
Product Status
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 16.0 Not-Affected

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EUVD-2026-58915 vulnerability details – vuln.today

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