CVE-2026-72339: Linux Vulnerability (CVSS 9.8)

Description

In the Linux kernel, the following vulnerability has been resolved: qede: fix off-by-one in BD ring consumption on build_skb failure qede_rx_build_skb() and qede_tpa_rx_build_skb() do not check for a NULL return from qede_build_skb(). When it returns NULL under memory pressure, the functions still consume a BD from the ring before returning NULL. The callers then recycle additional BDs, resulting in one extra BD being consumed (off-by-one). This desynchronizes the BD ring, which can corrupt DMA page reference counts and lead to SLUB freelist corruption. Commit 4e910dbe3650 ("qede: confirm skb is allocated before using") added a NULL check inside qede_build_skb() to prevent a NULL pointer dereference, but did not address the missing NULL checks in the callers, making this off-by-one reachable. Fix this by adding NULL checks for the return value of qede_build_skb() in both qede_rx_build_skb() and qede_tpa_rx_build_skb(), returning NULL immediately before any BD ring manipulation.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.22%

12.8th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
Linux	Linux	>= 8a8633978b842c88fbcfe00d4e5dde96048f630e, < ecc05d4b20220a09c9c69584fc46ca55248a374a; >= 8a8633978b842c88fbcfe00d4e5dde96048f630e, < 07be8b8adf91b7ada4c3dacce064d572a6066421; >= 8a8633978b842c88fbcfe00d4e5dde96048f630e, < 1624aa100c0b218181aa74e3696a389b509298cb; >= 8a8633978b842c88fbcfe00d4e5dde96048f630e, < 0bf78df2d3ecb1f4964ff42a7327d25845955153; >= 8a8633978b842c88fbcfe00d4e5dde96048f630e, < 814a5edac8c9fc04051808d5faaa93768e989281; >= 8a8633978b842c88fbcfe00d4e5dde96048f630e, < b066420e57f3402a52c998678b4678252ac9bb63; >= 8a8633978b842c88fbcfe00d4e5dde96048f630e, < 982d6d6bc059c5dff37a2201c2f08c14bcfcbd20; >= 8a8633978b842c88fbcfe00d4e5dde96048f630e, < a0a558ca7e75b49e71f8c545c30e8c005e6e4e2f
Linux	Linux	4.18

References

Timeline

Published: Aug 15, 2026
Last Modified: Aug 17, 2026
Status: Received

Frequently Asked Questions

What is CVE-2026-72339?

In the Linux kernel, the following vulnerability has been resolved: qede: fix off-by-one in BD ring consumption on build_skb failure qede_rx_build_skb() and qede_tpa_rx_build_skb() do not check for a NULL return from qede_build_skb(). When it returns NULL under memory pressure, the functions still consume a BD from the ring before returning NULL. The callers then recycle additional BDs, resulting in one extra BD being consumed (off-by-one). This desynchronizes the BD ring, which can corrupt DMA page reference counts and lead to SLUB freelist corruption. Commit 4e910dbe3650 ("qede: confirm skb is allocated before using") added a NULL check inside qede_build_skb() to prevent a NULL pointer dereference, but did not address the missing NULL checks in the callers, making this off-by-one reachable. Fix this by adding NULL checks for the return value of qede_build_skb() in both qede_rx_build_skb() and qede_tpa_rx_build_skb(), returning NULL immediately before any BD ring manipulation.

How severe is CVE-2026-72339?

CVE-2026-72339 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.22% probability of exploitation in the next 30 days.

How do I fix CVE-2026-72339?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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