CVE-2026-46244: netfilter: nft_inner: Fix IPv6 inner_thoff desync
Vulnerability summary
CVE-2026-46244 is a critical (CVSS 9.1) Incorrect Calculation vulnerability in linux. EPSS estimates a 0.42% chance of exploitation in the next 30 days, higher than 36.1% of scored vulnerabilities.
Severe, CVSS 9.1 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 0% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 43 · Related 41Timeline
- 03-06-2026PublishedVulnerability first disclosed.
- 19-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_inner: Fix IPv6 inner_thoff desync In nft_inner_parse_l2l3(), when processing inner IPv6 packets, ipv6_find_hdr() correctly computes the transport header offset traversing all extension headers, but the result is immediately overwritten with nhoff + sizeof(_ip6h) (40 bytes), which only accounts for the IPv6 base header. This creates a desync between inner_thoff (wrong — points to extension header start) and l4proto (correct — e.g., IPPROTO_TCP), enabling transport header forgery and potential firewall bypass. This issue affects stable versions from Linux 6.2. For comparison, the normal (non-inner) IPv6 path correctly preserves ipv6_find_hdr()'s result. Removing the incorrect overwrite ensures that ipv6_find_hdr()'s calculated transport header offset is preserved, thereby fixing the desynchronization.
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated9.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- OSV · DebianEcosystem advisory · calculated9.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- NVDNIST9.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS trend
Probability
0.42%
Chance of exploitation in the next 30 days
Percentile
36%
Versus all other CVEs
30-day change
Decrease -0.04 pp
From 0.46% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-682Incorrect CalculationThe product performs a calculation that generates incorrect or unintended results that are later used in security-critical decisions or resource management.
- CWE-823Use of Out-of-range Pointer OffsetThe product performs pointer arithmetic on a valid pointer, but it uses an offset that can point outside of the intended range of valid memory locations for the resulting pointer.
Affected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu136 products
- linux< 6.8.0-134.134 | < 6.17.0-40.40 | < 7.0.0-27.27
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 6.8.0-1060.63 | < 6.17.0-1019.19 | < 7.0.0-1008.8
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 3a07327d10a09379315c844c63f27941f5081e0a, < c161ad9157f5a0429b5ff94d9770faf3bf48d273 | ≥ 3a07327d10a09379315c844c63f27941f5081e0a, < 870d59e2cf218e7418491e26bad768cb16654582 | ≥ 3a07327d10a09379315c844c63f27941f5081e0a, < 689bbf48c1f45130086ae1c46ab83ea4c753c601 | ≥ 3a07327d10a09379315c844c63f27941f5081e0a, < d0f98a3617f6ae5b1e95cde1e68e7ead4a1279ce | ≥ 3a07327d10a09379315c844c63f27941f5081e0a, < b6a91f68ebfed9c38e0e9150f58a9b85da07181c | 6.2
- linux_kernel≥ 6.2, < 6.6.142 | ≥ 6.7, < 6.12.92 | ≥ 6.13, < 6.18.34 | ≥ 6.19, < 7.0.11 | 7.1:rc1 | 7.1:rc2 | 7.1:rc3 | 7.1:rc4
Debian1 product
- linux< 6.12.94-1 | < 7.0.12-1
3 vendors · 139 products
