CVE-2026-53362: Linux kernel · ipv6: account for fraggap on the paged allocation path
Affects Linux kernelSource GCVE Database
Exploited in the wild · KEV due 30 Aug 2026 · fixed in 7.0.0-31.31~24.04.1 : patch Linux kernel now.
Data as of 26 Oct 2026, 14:05 UTC
- KEV deadline
- US federal agencies must patch by this date; a sensible deadline for everyone else. Other KEV due dates
- EPSS
- 0.7% chance of exploitation in 30 days – higher than 53% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0-31.31~24.04.1, 7.0.0-31.31, 7.0.0-1012.12 +7
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 4 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: evidence found.
Listed in CISA KEV 54 days after disclosure
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE published
on cve.org
, t = 0
In Threat Radar
record ingested
, 13 days after disclosure
Added to CISA KEV (opens in a new tab)
exploitation confirmed
, 54 days after disclosure
KEV remediation due
US federal deadline
, 57 days after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
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.
References
- ubuntu.com/security/CVE-2026-53362 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-53362 (opens in a new tab)
- git.kernel.org/linus/736b380e28d0480c7bc3e022f1950f31fe53a7c5 (opens in a new tab)
- git.kernel.org/stable/c/14200d435af9a9eeb444f529fc2f689a236b7962 (opens in a new tab)
- git.kernel.org/stable/c/46f201f8b4c39633a1fa3dc12459f506d470993d (opens in a new tab)
- git.kernel.org/stable/c/6374fb9edf72c67a118a2c214a0dddd04c921e0a (opens in a new tab)
- git.kernel.org/stable/c/65fb14cbebb0cd0eff903a22d33537ddc8b95769 (opens in a new tab)
- git.kernel.org/stable/c/736b380e28d0480c7bc3e022f1950f31fe53a7c5 (opens in a new tab)
- git.kernel.org/stable/c/e9eacf19281ea2498b36291b56c9606118c2d74e (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:35840 (opens in a new tab)
- access.redhat.com/security/updates/classification/ (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2495904 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_35840.json (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:34927 (opens in a new tab)
- docs.redhat.com/en/documentation/red_hat_enterprise_linux_for_nvidia/26.01/html/26.01_release_notes/index (opens in a new tab)
- issues.redhat.com/browse/VOYAGER-1213 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_34927.json (opens in a new tab)
- cisa.gov/known-exploited-vulnerabilities-catalog (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)