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NVD / CVE Program· CNA mitre

CVE-2016-5696: net/ipv4/tcp_input.c in the Linux kernel before 4.7 does not properly determine the rate of challenge ACK segments, which makes it easier…

MediumCVSS 4.8 · v3.0—Proof of concept Fix available

Noroxi assessment

Priority: Monitor (action score 23/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 14.5% (FIRST EPSS); higher than 96.6% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: linux (Debian:12) 4.7.2-1; linux (Debian:7) 3.2.81-2; linux (Debian:8) 3.16.36-1+deb8u1.

Low priority for now. Upgrade to linux (Debian:12) 4.7.2-1; linux (Debian:7) 3.2.81-2; linux (Debian:8) 3.16.36-1+deb8u1 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

net/ipv4/tcp_input.c in the Linux kernel before 4.7 does not properly determine the rate of challenge ACK segments, which makes it easier for remote attackers to hijack TCP sessions via a blind in-window attack.

Published
Aug 6, 2016
Updated
Jun 16, 2026
EPSS
14.5% · 96th percentile

Report tools

JSON

Action score

23

Monitor

Low priority for now.

CVSS
19 / 40 · 4.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
4 / 30 · 14.5%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

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  • when exploit code appears or is weaponized
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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.

VendorProduct
linuxlinux kernel
googleandroid
oraclevm server

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • google androidup to 7.0 inclusive
  • linux linux kernelup to 4.6.6 inclusive
  • oracle vm server3.3
  • oracle vm server3.4

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 4.7.2-14.7.2-1
Debian:7linuxbefore 3.2.81-23.2.81-2
Debian:8linuxbefore 3.16.36-1+deb8u13.16.36-1+deb8u1
Red Hat:enterprise_linux:6::clientkernelbefore 0:2.6.32-642.4.2.el60:2.6.32-642.4.2.el6
Red Hat:enterprise_linux:6::clientkernel-abi-whitelistsbefore 0:2.6.32-642.4.2.el60:2.6.32-642.4.2.el6
Red Hat:enterprise_linux:6::clientkernel-debugbefore 0:2.6.32-642.4.2.el60:2.6.32-642.4.2.el6
Red Hat:enterprise_linux:6::clientkernel-debug-debuginfobefore 0:2.6.32-642.4.2.el60:2.6.32-642.4.2.el6
Red Hat:enterprise_linux:6::clientkernel-debug-develbefore 0:2.6.32-642.4.2.el60:2.6.32-642.4.2.el6
Red Hat:enterprise_linux:6::clientkernel-debuginfobefore 0:2.6.32-642.4.2.el60:2.6.32-642.4.2.el6
Red Hat:enterprise_linux:6::clientkernel-debuginfo-common-i686before 0:2.6.32-642.4.2.el60:2.6.32-642.4.2.el6
Red Hat:enterprise_linux:6::clientkernel-debuginfo-common-x86_64before 0:2.6.32-642.4.2.el60:2.6.32-642.4.2.el6
Red Hat:enterprise_linux:6::clientkernel-develbefore 0:2.6.32-642.4.2.el60:2.6.32-642.4.2.el6
Red Hat:enterprise_linux:6::clientkernel-docbefore 0:2.6.32-642.4.2.el60:2.6.32-642.4.2.el6
Red Hat:enterprise_linux:6::clientkernel-firmwarebefore 0:2.6.32-642.4.2.el60:2.6.32-642.4.2.el6
Red Hat:enterprise_linux:6::clientkernel-headersbefore 0:2.6.32-642.4.2.el60:2.6.32-642.4.2.el6
Red Hat:enterprise_linux:6::clientperfbefore 0:2.6.32-642.4.2.el60:2.6.32-642.4.2.el6
Red Hat:enterprise_linux:6::clientperf-debuginfobefore 0:2.6.32-642.4.2.el60:2.6.32-642.4.2.el6
Red Hat:enterprise_linux:6::clientpython-perfbefore 0:2.6.32-642.4.2.el60:2.6.32-642.4.2.el6
Red Hat:enterprise_linux:6::clientpython-perf-debuginfobefore 0:2.6.32-642.4.2.el60:2.6.32-642.4.2.el6
Red Hat:enterprise_linux:6::serverkernel-bootwrapperbefore 0:2.6.32-642.4.2.el60:2.6.32-642.4.2.el6
Red Hat:enterprise_linux:6::serverkernel-debuginfo-common-ppc64before 0:2.6.32-642.4.2.el60:2.6.32-642.4.2.el6
Red Hat:enterprise_linux:6::serverkernel-debuginfo-common-s390xbefore 0:2.6.32-642.4.2.el60:2.6.32-642.4.2.el6
Red Hat:enterprise_linux:6::serverkernel-kdumpbefore 0:2.6.32-642.4.2.el60:2.6.32-642.4.2.el6
Red Hat:enterprise_linux:6::serverkernel-kdump-debuginfobefore 0:2.6.32-642.4.2.el60:2.6.32-642.4.2.el6

+96

Same product

linux: all records

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Published before and after this one in the same product

  • ← EarlierCVE-2016-5400Aug 6, 2016 · Memory leak in the airspy_probe function in drivers/media/usb/airspy/airspy.c in the airspy USB driver in the Linux kernel before 4.7…
    17Monitor
  • ← EarlierCVE-2016-5412Aug 6, 2016 · arch/powerpc/kvm/book3s_hv_rmhandlers.S in the Linux kernel through 4.7 on PowerPC platforms, when CONFIG_KVM_BOOK3S_64_HV is enabled…
    26Monitor
  • Later →CVE-2016-6136Aug 6, 2016 · Race condition in the audit_log_single_execve_arg function in kernel/auditsc.c in the Linux kernel through 4.7 allows local users to bypass…
    18Monitor

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
debian:linux4.7.2-1 · Debian:12Package registry (OSV)
red hat:kernel-rt1:3.10.0-327.rt56.195.el6rt · Red Hat:enterprise_mrg:2:server:el6Package registry (OSV)
red hat:kernel-rt-debug1:3.10.0-327.rt56.195.el6rt · Red Hat:enterprise_mrg:2:server:el6Package registry (OSV)
red hat:kernel-rt-debug-debuginfo1:3.10.0-327.rt56.195.el6rt · Red Hat:enterprise_mrg:2:server:el6Package registry (OSV)
red hat:kernel-rt-debug-devel1:3.10.0-327.rt56.195.el6rt · Red Hat:enterprise_mrg:2:server:el6Package registry (OSV)
red hat:kernel-rt-debuginfo1:3.10.0-327.rt56.195.el6rt · Red Hat:enterprise_mrg:2:server:el6Package registry (OSV)
red hat:kernel-rt-debuginfo-common-x86_641:3.10.0-327.rt56.195.el6rt · Red Hat:enterprise_mrg:2:server:el6Package registry (OSV)
red hat:kernel-rt-devel1:3.10.0-327.rt56.195.el6rt · Red Hat:enterprise_mrg:2:server:el6Package registry (OSV)
red hat:kernel-rt-doc1:3.10.0-327.rt56.195.el6rt · Red Hat:enterprise_mrg:2:server:el6Package registry (OSV)
red hat:kernel-rt-firmware1:3.10.0-327.rt56.195.el6rt · Red Hat:enterprise_mrg:2:server:el6Package registry (OSV)
red hat:kernel-rt-trace1:3.10.0-327.rt56.195.el6rt · Red Hat:enterprise_mrg:2:server:el6Package registry (OSV)
red hat:kernel-rt-trace-debuginfo1:3.10.0-327.rt56.195.el6rt · Red Hat:enterprise_mrg:2:server:el6Package registry (OSV)
red hat:kernel-rt-trace-devel1:3.10.0-327.rt56.195.el6rt · Red Hat:enterprise_mrg:2:server:el6Package registry (OSV)
suse:kernel-bigmem3.0.101-88.1 · SUSE:Linux Enterprise Server 11 SP4Package registry (OSV)
suse:kernel-default3.12.67-60.64.18.1 · SUSE:Linux Enterprise Desktop 12 SP1Package registry (OSV)
suse:kernel-docs3.12.67-60.64.18.3 · SUSE:Linux Enterprise Software Development Kit 12 SP1Package registry (OSV)
suse:kernel-ec23.12.67-60.64.18.1 · SUSE:Linux Enterprise Module for Public Cloud 12Package registry (OSV)
suse:kernel-obs-build3.12.67-60.64.18.1 · SUSE:Linux Enterprise Software Development Kit 12 SP1Package registry (OSV)
suse:kernel-pae3.0.101-88.1 · SUSE:Linux Enterprise Server 11 SP4Package registry (OSV)
suse:kernel-ppc643.0.101-88.1 · SUSE:Linux Enterprise Server 11 SP4Package registry (OSV)
suse:kernel-source3.12.67-60.64.18.1 · SUSE:Linux Enterprise Desktop 12 SP1Package registry (OSV)
suse:kernel-syms3.12.67-60.64.18.1 · SUSE:Linux Enterprise Desktop 12 SP1Package registry (OSV)
suse:kernel-trace3.0.101-88.1 · SUSE:Linux Enterprise Server 11 SP4Package registry (OSV)
suse:kernel-xen3.12.67-60.64.18.1 · SUSE:Linux Enterprise Desktop 12 SP1Package registry (OSV)
suse:kgraft-patch-SLE12-SP1_Update_91-6.3 · SUSE:Linux Enterprise Live Patching 12Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×5

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHub5 repositories2016-08-20 → 2016-12-07

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.

  1. Published
  2. First PoC+13 d
  3. TodayNov 15, 2026+3753 d

Patch and commit links

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

Not on record for this CVE: EPSS history · researcher credit · variant or chain candidate · public bounty program.

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.
  • Special conditions such as timing or configuration are required.

If successful

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

Weakness class (CWE)

CWE-200 · Exposure of Sensitive Information to an Unauthorized Actor

CVSS vector

CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L

nvd-primary

Root cause

The extension requests broader permissions than its function needs and sends the data it collects out for purposes beyond its stated function.

The bug in code

The whole CWE-200 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

json
{  "permissions": ["tabs", "<all_urls>"],  "background": { "service_worker": "analytics.js" }}

Fixed

json
{  "permissions": ["activeTab"],  "host_permissions": ["https://yildiz.example/*"]}

Attack context

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

References

Show all references (19 more)

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

All records