Linux Kernel up to 7.2-rc2 netfilter net/ipv6/reassembly.c nf_ct_frag6_reasm state issue

CVSS Meta Temp Score
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CTI Interest Score
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9.5$5k-$25k0.48

Summaryinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 7.2-rc2. Affected is the function nf_ct_frag6_reasm of the file net/ipv6/reassembly.c of the component netfilter. Such manipulation leads to state issue. This vulnerability is documented as CVE-2026-72250. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in Linux Kernel up to 7.2-rc2 and classified as very critical. Affected by this issue is the function nf_ct_frag6_reasm of the file net/ipv6/reassembly.c of the component netfilter. The manipulation with an unknown input leads to a state issue vulnerability. Using CWE to declare the problem leads to CWE-371. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_reasm: guard mac_header adjustment after IPv6 defrag nf_ct_frag6_reasm() slides the packet head forward to drop the IPv6 fragment header and then unconditionally advances skb->mac_header: skb->mac_header += sizeof(struct frag_hdr); On the NF_INET_LOCAL_OUT defrag path the skb has no link-layer header yet, so skb->mac_header is still the "not set" sentinel (u16)~0U. Adding sizeof(struct frag_hdr) wraps it to a small value (0xffff + 8 == 7), after which skb_mac_header_was_set() wrongly reports a MAC header is present and skb_mac_header() points into the headroom. The reassembler has done this unconditional add since it was introduced; it was harmless while mac_header was a bare pointer, but wrong once mac_header became a u16 offset whose unset state is the ~0U sentinel tested by skb_mac_header_was_set(). The sibling net/ipv6/reassembly.c does the same relocation and does guard the adjustment; mirror the guard here.

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2026-72250 since 08/09/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 08/15/2026).

Upgrading to version 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.5 or 7.2-rc3 eliminates this vulnerability. Applying the patch 6e8cd710ca35c576f5f2e5a396047c9ac61f75e5/2a95ec21824a8ad81ad660b12231456fc0ac9830/bbcdef2061b170af45702ce6b359c02c12acfc94/cd0d7bbc027b4d3329712cdcdeb4e5567ffd0d58/53ef70a315420ed31581d38343684b3bf9a3c76d/a58230f3a7c4f6c3261786bc1efb72c42e68cd25/00bdce2fda7e430d24cfbc96764a1b96deb31f82/3b08fed5b7e0d5e3a25d73ef3ba09cd33ade16c9 is able to eliminate this problem.

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Productinfo

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Version

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 10.0
VulDB Meta Temp Score: 9.5

VulDB Base Score: 10.0
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: State issue
CWE: CWE-371
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.261/5.15.212/6.1.178/6.6.145/6.12.97/6.18.40/7.1.5/7.2-rc3
Patch: 6e8cd710ca35c576f5f2e5a396047c9ac61f75e5/2a95ec21824a8ad81ad660b12231456fc0ac9830/bbcdef2061b170af45702ce6b359c02c12acfc94/cd0d7bbc027b4d3329712cdcdeb4e5567ffd0d58/53ef70a315420ed31581d38343684b3bf9a3c76d/a58230f3a7c4f6c3261786bc1efb72c42e68cd25/00bdce2fda7e430d24cfbc96764a1b96deb31f82/3b08fed5b7e0d5e3a25d73ef3ba09cd33ade16c9

Timelineinfo

08/09/2026 CVE reserved
08/15/2026 +6 days Advisory disclosed
08/15/2026 +0 days VulDB entry created
08/15/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-72250 (🔒)
GCVE (CVE): GCVE-0-2026-72250
GCVE (VulDB): GCVE-100-390686

Entryinfo

Created: 08/15/2026 14:00
Changes: 08/15/2026 14:00 (60)
Complete: 🔍
Cache ID: 216::103

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