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Linux KernelOperating system · Linux

CVE-2026-53002

CRITICAL · 9.8 CVSS v3.1 Published 2026-06-24
Fix available
A fix is available. Upgrade to 5.10.258 / 5.15.209 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click 8 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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 [..]

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Buffer overflow vulnerability in Linux kernel's netfilter conntrack module where sprintf is used instead of scnprintf in mangle_content_len(), leading to stack-out-of-bounds write. The issue occurs during SIP/SDP session processing via nf_nat_sdp_session, potentially allowing kernel memory corruption.

MitigationReplace sprintf with scnprintf and ensure adequate buffer sizing in mangle_content_len() function per the upstream kernel patch.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 2.6.20, < 5.10.258>= 5.11, < 5.15.209>= 5.16, < 6.1.175>= 6.2, < 6.6.141>= 6.7, < 6.12.91>= 6.13, < 6.18.33>= 6.19, < 7.0.10
Enterprise LinuxOperating system
Affected:= 7.0= 8.0= 9.0= 10.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify netfilter SIP support module
    Check if the SIP conntrack module is loaded: lsmod | grep -i 'nf_conntrack_sip' or modinfo nf_conntrack_sip
    Affected if Module is loaded and being used for SIP traffic handling
  2. Determine kernel version
    Run 'uname -r' or 'cat /proc/version' to obtain the kernel version
    Affected if Kernel version falls within the vulnerable range for this CVE (compare against published vulnerable versions)
  3. Check for active SIP NAT rules
    List iptables/nftables rules involving SIP: 'iptables -t nat -L -n' or 'nft list ruleset' and look for rules targeting port 5060 (SIP) with NAT target
    Affected if NAT rules for SIP traffic (port 5060) are configured, as the vulnerability occurs in the nf_nat_sdp_session path
  4. Verify SIP ALG support in kernel
    Check if SIP ALG (Application Layer Gateway) is enabled: grep -i sip /proc/net/nf_conntrack or check NAT configuration for SIP helper
    Affected if SIP ALG/helper is enabled in the conntrack/nat configuration, which activates the vulnerable mangle_content_len() code path
  5. Confirm KASAN detection capability
    Check if kernel has KASAN enabled: 'cat /boot/config-$(uname -r) | grep CONFIG_KASAN' or dmesg for KASAN messages
    Affected if KASAN is not compiled into the kernel, as the summary indicates this overflow was detected by KASAN in the original finding

Your environment is affected if you run a vulnerable kernel version, have the SIP conntrack module loaded, and use SIP NAT/ALG functionality which triggers the mangle_content_len() function in nf_nat_sdp_session.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to 5.10.258 / 5.15.209 / 6.1.175 or later
Fixed in 5.10.2585.15.2096.1.175
Interim mitigation

Replace sprintf with scnprintf and ensure adequate buffer sizing in mangle_content_len() function per the upstream kernel patch.

Fix this in Linux Kernel Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing8.0 h
  • Review / QA4.0 h
18.0 hours of engineering $3,040
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-53002 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data