CVE-2026-53362: Linux Kernel

What is CVE-2026-53362?

In the Linux kernel, the following vulnerability has been resolved: ipv6: account for fraggap on the paged allocation path In __ip6_append_data(), when the paged-allocation branch is taken (MSG_MORE / NETIF_F_SG / large fraglen), alloclen and pagedlen are computed as alloclen = fragheaderlen + transhdrlen; pagedlen = datalen - transhdrlen; datalen already includes fraggap (datalen = length + fraggap). When fraggap is non-zero, this is not the first skb and transhdrlen is zero. The fraggap bytes carried over from the previous skb are copied just past the fragment headers in the new skb's linear area. The linear area is therefore undersized by fraggap bytes while pagedlen is overstated by the same amount, and the copy writes past skb->end into the trailing skb_shared_info. An unprivileged user can trigger this via a UDPv6 socket using MSG_MORE together with MSG_SPLICE_PAGES. The bad accounting was introduced by commit 773ba4fe9104 ("ipv6: avoid partial copy for zc"). Before commit ce650a166335 ("udp6: Fix __ip6_append_data()'s handling of MSG_SPLICE_PAGES"), the negative copy value caused -EINVAL to be returned. That later commit allowed MSG_SPLICE_PAGES to proceed in this case, making the corruption triggerable. The non-paged branch sets alloclen to fraglen, which already accounts for fraggap because datalen does. Bring the paged branch in line by adding fraggap to alloclen and subtracting it from pagedlen. After this adjustment, copy no longer collapses to -fraggap on the paged path, so remove the stale comment describing that old arithmetic. Since a negative copy is no longer expected for a valid MSG_SPLICE_PAGES case, remove the MSG_SPLICE_PAGES exception from the negative copy check.

CVSS7.8 NVD 3.1

SeverityHIGH

Exploitation In the wild In CISA KEV

EPSS1% · P52

Triage statusActive Exploit

ActionPatch immediately

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

CWECWE-787, CWE-122

NVD published2026-07-04

NVD last modified2026-08-28

Timeline

2026-07-04Published to the U.S. National Vulnerability Database (NVD)
2026-08-27Added to the CISA Known Exploited Vulnerabilities (KEV) catalog
2026-08-28First covered in a defend.network daily briefing
2026-08-28NVD record last updated
2026-08-30CISA federal remediation deadline (BOD 22-01)

CISA Known Exploited Vulnerability

Linux Kernel Unspecified Vulnerability

Added to KEV2026-08-27

Federal patch deadline2026-08-30

Known ransomware useUnknown

Affected product

Linux Kernel

Remediation Steps

Apply the vendor security update for Linux Kernel as a priority.
Restrict network exposure of the affected service to trusted sources until patched.
Review logs and detections for indicators of exploitation.
Confirm fixed versions against the official vendor advisory before deploying.

References

Referenced in our briefings & reports

Vulnerability Priority Report – Week 1 of September 2026 (September 7 – 13)
Vulnerability Priority Report – Week 5 of August 2026 (August 31 – September 6)
Vulnerability Priority Report – Week 4 of August 2026 (August 24 – 30)
WordPress plugin RCEs, Linux kernel exploit, PaperCut bypass patch; Cosmos EVM drained (2026-08-30)
PaperCut second patch; Cosmos EVM drained; McKesson 284M records stolen (2026-08-29)
AI agents breach Hugging Face; Next.js, PaperCut RCEs exploited; TeamPCP arrests (2026-08-28)

Browse all tracked CVEs in the defend.network CVE database →

🤖 This CVE page is generated by defend.network from NVD, CISA KEV, EPSS, and our verified daily briefings. Severity and exploitation data come from official sources; always verify remediation steps against the official vendor advisory before acting in production.