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NVD / CVE Program· CNA Linux

CVE-2026-74569: netfilter: nf_conntrack_sip: widen NAT rewrite delta to s32 in sip_help_tcp()

Noroxi assessment

Priority: Monitor (action score 39/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.38% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: Linux Linux 1b0843f9e9b9b0b9b4b70d143b67e58163c85b2c, 32d4abc8923b0d4046fd63ad6e4917872e44eb6d, 63eea41759fd682229c14e0a2205802b46d106f3; azl3 kernel 6.6.150.1-1 on Azure Linux 3.0 6.6.152.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 1b0843f9e9b9b0b9b4b70d143b67e58163c85b2c, 32d4abc8923b0d4046fd63ad6e4917872e44eb6d, 63eea41759fd682229c14e0a2205802b46d106f3; azl3 kernel 6.6.150.1-1 on Azure Linux 3.0 6.6.152.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_sip: widen NAT rewrite delta to s32 in sip_help_tcp() sip_help_tcp() stores the size change of each NAT-rewritten SIP message in s16 diff and accumulates it in s16 tdiff, but a single message can grow by more than S16_MAX while the packet stays under the 65535 enlarge_skb() limit: nf_nat_sip() rewrites every matching URI, and a long Contact list expands the message by tens of kilobytes. diff then wraps, and "datalen = datalen + diff - msglen" yields a huge unsigned datalen, so the next iteration's ct_sip_get_header() reads past the linearized skb tail. Widen diff, tdiff and the seq_adjust hook to s32. Both are bounded by the 65535 byte packet limit, and the seqadj core is already s32 (nf_ct_seqadj_set() takes s32), so no previously accepted input is rejected. BUG: KASAN: use-after-free in ct_sip_get_header (net/netfilter/nf_conntrack_sip.c:464) Read of size 1 at addr ffff888010800000 by task ksoftirqd/1/25 ct_sip_get_header (net/netfilter/nf_conntrack_sip.c:464) sip_help_tcp (net/netfilter/nf_conntrack_sip.c:1694) nf_confirm (net/netfilter/nf_conntrack_proto.c:183) nf_hook_slow (net/netfilter/core.c:619) ip6_output (net/ipv6/ip6_output.c:246) ip6_forward (net/ipv6/ip6_output.c:690) ipv6_rcv (net/ipv6/ip6_input.c:351) __netif_receive_skb_one_core (net/core/dev.c:6212) process_backlog (net/core/dev.c:6676) __napi_poll (net/core/dev.c:7735) net_rx_action (net/core/dev.c:7955) handle_softirqs (kernel/softirq.c:622) run_ksoftirqd (kernel/softirq.c:1076) ...

CriticalCVSS 9.8 · v3.1—No exploit Fix available
Published
Aug 15, 2026
Updated
Oct 16, 2026
EPSS
0.3% · 33th percentile
CWE
—

Report tools

JSON

Action score

39

Monitor

Low priority for now.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
9.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 2.6.34affected
    • f5b321bd37fbec9188feb1f721ab46a5ac0b35da and later · before ed1f9be6dc8e2e280b8725e44ccdc6e0cd38640daffected · git
    • f5b321bd37fbec9188feb1f721ab46a5ac0b35da and later · before 1b0843f9e9b9b0b9b4b70d143b67e58163c85b2caffected · git
    • f5b321bd37fbec9188feb1f721ab46a5ac0b35da and later · before 32d4abc8923b0d4046fd63ad6e4917872e44eb6daffected · git
    • f5b321bd37fbec9188feb1f721ab46a5ac0b35da and later · before 63eea41759fd682229c14e0a2205802b46d106f3affected · git
    • f5b321bd37fbec9188feb1f721ab46a5ac0b35da and later · before c97621a110e386b2dd69e276eb699e1d3cec581daffected · git
    • f5b321bd37fbec9188feb1f721ab46a5ac0b35da and later · before f74554e67ccf04d1fa71069e8c9afa2717e40716affected · git
    • f5b321bd37fbec9188feb1f721ab46a5ac0b35da and later · before ef5e2c6555d2bb52dfe0e4053a8c6193f9d83b64affected · git
    • f5b321bd37fbec9188feb1f721ab46a5ac0b35da and later · before db3d0e0e5d4bc5ab4fe445b9f413d1b486508ca5affected · git
    • before 2.6.34not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:10kernel-64k-debug-develbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-64k-debug-devel-matchedbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-64k-develbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-64k-devel-matchedbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-debug-develbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-debug-devel-matchedbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-develbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-devel-matchedbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-docbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-headersbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-zfcpdump-develbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-zfcpdump-devel-matchedbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10perfbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10python3-perfbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
Debian:12linuxbefore 6.1.187-16.1.187-1
Debian:12linux-6.12before 6.12.107-1~deb12u16.12.107-1~deb12u1
Debian:13linuxbefore 6.12.105-16.12.105-1
Debian:14linuxbefore 7.1.8-17.1.8-1
Red Hat:enterprise_linux:10.2kernelbefore 0:6.12.0-211.59.1.el10_20:6.12.0-211.59.1.el10_2
Red Hat:enterprise_linux:10.2kernel-64kbefore 0:6.12.0-211.59.1.el10_20:6.12.0-211.59.1.el10_2
Red Hat:enterprise_linux:10.2kernel-64k-corebefore 0:6.12.0-211.59.1.el10_20:6.12.0-211.59.1.el10_2
Red Hat:enterprise_linux:10.2kernel-64k-debugbefore 0:6.12.0-211.59.1.el10_20:6.12.0-211.59.1.el10_2
Red Hat:enterprise_linux:10.2kernel-64k-debug-corebefore 0:6.12.0-211.59.1.el10_20:6.12.0-211.59.1.el10_2
Red Hat:enterprise_linux:10.2kernel-64k-debug-debuginfobefore 0:6.12.0-211.59.1.el10_20:6.12.0-211.59.1.el10_2

+84

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-74567Aug 15, 2026 · keys: fix out-of-bounds read in keyring_get_key_chunk()
    28Monitor
  • ← EarlierCVE-2026-74568Aug 15, 2026 · KVM: arm64: vgic: Fix race between LPI release and re-registration
    37Monitor
  • Later →CVE-2026-74571Aug 15, 2026 · btrfs: skip global block reserve accounting for rescue mounts
    0Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux1b0843f9e9b9b0b9b4b70d143b67e58163c85b2cVendor (CNA)
Linux Linux32d4abc8923b0d4046fd63ad6e4917872e44eb6dVendor (CNA)
Linux Linux63eea41759fd682229c14e0a2205802b46d106f3Vendor (CNA)
Linux Linuxc97621a110e386b2dd69e276eb699e1d3cec581dVendor (CNA)
Linux Linuxdb3d0e0e5d4bc5ab4fe445b9f413d1b486508ca5Vendor (CNA)
Linux Linuxed1f9be6dc8e2e280b8725e44ccdc6e0cd38640dVendor (CNA)
Linux Linuxef5e2c6555d2bb52dfe0e4053a8c6193f9d83b64Vendor (CNA)
Linux Linuxf74554e67ccf04d1fa71069e8c9afa2717e40716Vendor (CNA)
azl3 kernel 6.6.150.1-1 on Azure Linux 3.06.6.152.1-1 · Release NotesMicrosoft (MSRC)
almalinux:kernel-64k-debug-devel6.12.0-211.59.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched6.12.0-211.59.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-devel6.12.0-211.59.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-devel-matched6.12.0-211.59.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-debug-devel6.12.0-211.59.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-debug-devel-matched6.12.0-211.59.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-devel6.12.0-211.59.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-devel-matched6.12.0-211.59.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-doc6.12.0-211.59.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-headers6.12.0-211.59.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-zfcpdump-devel6.12.0-211.59.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-zfcpdump-devel-matched6.12.0-211.59.1.el10_2 · AlmaLinux:10Package registry (OSV)
debian:linux6.1.187-1 · Debian:12Package registry (OSV)
debian:linux-6.126.12.107-1~deb12u1 · Debian:12Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:6.12.0-211.59.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debug-devel0:6.12.0-211.59.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debug-devel-matched0:6.12.0-211.59.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debuginfo0:6.12.0-211.59.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-devel0:6.12.0-211.59.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-devel-matched0:6.12.0-211.59.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debug-debuginfo0:6.12.0-211.59.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)

+5

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records