CVE-2026-53002 — Linux kernel netfilter conntrack out-of-bounds write in SIP helper
In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack: remove sprintf usage Replace it with scnprintf, the buffer sizes are expected to be large enough to hold the result, no need for snprintf+overflow check. Increase buffer size in mangle_content_len() while at it. BUG: KASAN: stack-out-of-bounds in vsnprintf+0xea5/0x1270 Write of size 1 at addr [..] vsnprintf+0xea5/0x1270 sprintf+0xb1/0xe0 mangle_content_len+0x1ac/0x280 nf_nat_sdp_session+0x1cc/0x240 process_sdp+0x8f8/0xb80 process_invite_request+0x108/0x2b0 process_sip_msg+0x5da/0xf50 sip_help_tcp+0x45e/0x780 nf_confirm+0x34d/0x990 [..]
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.4% (30-day exploitation probability)+4
- Technical severity (critical)+10
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel, Red Hat Enterprise Linux).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
version 2.6.20≥ 9fafcd7b203229c3f3893a475741afc27e276306 and < 6e7066bdb481a87fe88c4fa563e348c03b2d373d≥ 9fafcd7b203229c3f3893a475741afc27e276306 and < c08ff52e44945e6ef4ce0790f49ea761b060c45b≥ 9fafcd7b203229c3f3893a475741afc27e276306 and < 8e3be0d12615a173fe260cd42753ca7a001acbf2≥ 9fafcd7b203229c3f3893a475741afc27e276306 and < a8e0a32a23d3f34862af3b4da792ecb3a891a9a3≥ 9fafcd7b203229c3f3893a475741afc27e276306 and < 1c9fb8aeed06790d42cdcd00f6c3ce0b9e926c1e≥ 9fafcd7b203229c3f3893a475741afc27e276306 and < ab64e61c9323fa6de21bd20da1ddb29a0fb65d34≥ 9fafcd7b203229c3f3893a475741afc27e276306 and < 6bbf829b4c1b44c941c47dd0d710f1393258f3d5 and 1 more≥ 9fafcd7b203229c3f3893a475741afc27e276306 and < 2f793ba78470a99f40389b7dc60a81d9f5ad3956 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel | ≥ 6.19 and < 7.0.10≥ 6.13 and < 6.18.33≥ 6.7 and < 6.12.91≥ 6.2 and < 6.6.141≥ 5.16 and < 6.1.175≥ 5.11 and < 5.15.209≥ 2.6.20 and < 5.10.258 | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Enterprise Linux | version 7.0version 10.0version 9.0version 8.0 | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 9.8 | CVSS 3.1 | Critical | 3.9 | 5.9 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database |
| 9.8 | CVSS 3.1 | Critical | — | — | GitHub, Inc. via GitHub Security Advisories |
| 9.8 | CVSS 3.1 | Critical | — | — | Linux via CVE Program (cve.org) e CISA ADP |
| 7.0 | CVSS 3.1 | High | 1.0 | 5.9 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c via NIST National Vulnerability Database |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.37%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Analysis and videos
CVE-2026-53002: Linux kernel netfilter conntrack out-of-bounds write in SIP helper
A fixed Linux kernel flaw in netfilter conntrack allows an out-of-bounds write (CWE-787) during SIP helper processing of SDP content used for NAT, as reported by KASAN. The CNA scores it 9.8 (Critical) with CVSS 3.1, and the record links eight stable-branch patches. No confirmed active exploitation appears in the sources consulted, and it is not listed in CISA KEV.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- Fix documented
- CVSS changed · 9.8
- Source status changed · → Modified
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 15, 2026 – Oct 15, 2026
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
18 on the record
- git.kernel.org/stable/c/1c9fb8aeed06790d42cdcd00f6c3ce0b9e926c1e
- git.kernel.org/stable/c/2f793ba78470a99f40389b7dc60a81d9f5ad3956
- git.kernel.org/stable/c/8e3be0d12615a173fe260cd42753ca7a001acbf2
- git.kernel.org/stable/c/c08ff52e44945e6ef4ce0790f49ea761b060c45b
- git.kernel.org/stable/c/6bbf829b4c1b44c941c47dd0d710f1393258f3d5
- git.kernel.org/stable/c/a8e0a32a23d3f34862af3b4da792ecb3a891a9a3
- git.kernel.org/stable/c/ab64e61c9323fa6de21bd20da1ddb29a0fb65d34
- git.kernel.org/stable/c/6e7066bdb481a87fe88c4fa563e348c03b2d373d
- nvd.nist.gov/vuln/detail/CVE-2026-53002
- access.redhat.com/errata/RHSA-2026:66000
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53002.json
- access.redhat.com/errata/RHSA-2026:66180
- access.redhat.com/security/cve/CVE-2026-53002
- github.com/advisories/GHSA-2256-5c36-mwcj
- cert-portal.siemens.com/productcert/html/ssa-019113.html
- access.redhat.com/errata/RHSA-2026:64770
- bugzilla.redhat.com/show_bug.cgi
- cert-portal.siemens.com/productcert/html/ssa-457936.html
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 10h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 10h
- Unknown CVE-2026-98431 RDMA/uverbs: Fix mmap_lock/disassociation_lock circular dependency 1d
- Unknown CVE-2026-98430 RDMA/efa: Keep admin queues alive while IRQ is registered 1d
- Unknown CVE-2026-98429 RDMA/efa: Keep EQ resources alive while IRQ is registered 1d
- Unknown CVE-2026-98428 ALSA: usb: 6fire: Avoid embedded URBs 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CISA SSVC assessment.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-53002 is "Linux kernel netfilter conntrack out-of-bounds write in SIP helper", rated Critical. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.8 describes technical severity. EPSS 0.37% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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