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NVD / CVE Program· CNA Linux

CVE-2026-74256: bpf, sockmap: fix integer overflow in bpf_msg_pop_data() bounds check

Noroxi assessment

Priority: Monitor (action score 33/100)

  • 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: 0.18% (FIRST EPSS).
  • Someone with local access to the system can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 17eb9832a10db2f7a80cb429ca2bc5038445a943, 9ef44ed6fb0c1db01cfcc3de432a33e719713eb5, a48802fb2cd2d1e23651989f8ff4d15e9d5dad54.

Low priority for now. Upgrade to Linux Linux 17eb9832a10db2f7a80cb429ca2bc5038445a943, 9ef44ed6fb0c1db01cfcc3de432a33e719713eb5, a48802fb2cd2d1e23651989f8ff4d15e9d5dad54 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: bpf, sockmap: fix integer overflow in bpf_msg_pop_data() bounds check start and len are u32, so u64 last = start + len; evaluates start + len in 32-bit and wraps before storing it in last. The bounds check if (start >= offset + l || last > msg->sg.size) return -EINVAL; can then be passed with an out-of-range start/len, after which the pop loop runs off the end of the scatterlist and sk_msg_shift_left() calls put_page() on the empty msg->sg.end slot: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] RIP: 0010:sk_msg_shift_left net/core/filter.c:2957 [inline] RIP: 0010:____bpf_msg_pop_data net/core/filter.c:3103 [inline] RIP: 0010:bpf_msg_pop_data+0x753/0x1a10 net/core/filter.c:2984 Call Trace: <TASK> bpf_prog_4cc92c278f4d5d56+0x1b1/0x1e8 bpf_prog_run_pin_on_cpu+0x107/0x320 include/linux/filter.h:746 sk_psock_msg_verdict+0x357/0x7f0 net/core/skmsg.c:934 tcp_bpf_send_verdict net/ipv4/tcp_bpf.c:420 [inline] tcp_bpf_sendmsg+0x766/0x1ae0 net/ipv4/tcp_bpf.c:583 __sock_sendmsg+0x153/0x1c0 net/socket.c:802 __sys_sendto+0x326/0x430 net/socket.c:2265 __x64_sys_sendto+0xe3/0x100 net/socket.c:2268 do_syscall_64+0x14c/0x480 entry_SYSCALL_64_after_hwframe+0x77/0x7f </TASK> Widen the addition with a (u64) cast so the bound is evaluated in 64-bit and a len near U32_MAX no longer wraps below msg->sg.size. While here, change pop from int to u32. It counts bytes against the unsigned scatterlist lengths and can never be negative, so the signed type only invites sign-confusion in the pop loop.

HighCVSS 8.4 · v3.1—No exploit Fix available
Published
Aug 15, 2026
Updated
Oct 16, 2026
EPSS
0.1% · 8th percentile
CWE
—

Report tools

JSON

Action score

33

Monitor

Low priority for now.

CVSS
33 / 40 · 8.4 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
8.4
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.

Get told when this record changes

  • 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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Follow CVE-2026-74256

When you'll hear from us

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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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

    • 5.0affected
    • 7246d8ed4dcce23f7509949a77be15fa9f0e3d28 and later · before 9ef44ed6fb0c1db01cfcc3de432a33e719713eb5affected · git
    • 7246d8ed4dcce23f7509949a77be15fa9f0e3d28 and later · before d693c5ed67dabe1ccbf8dcea93075bdc9ffd4ca0affected · git
    • 7246d8ed4dcce23f7509949a77be15fa9f0e3d28 and later · before ba5cc05dae8fce237d191c7ea96b1107a791e548affected · git
    • 7246d8ed4dcce23f7509949a77be15fa9f0e3d28 and later · before c05a0ec1cdced622a1a0c7d85679fe02f31033ecaffected · git
    • 7246d8ed4dcce23f7509949a77be15fa9f0e3d28 and later · before 17eb9832a10db2f7a80cb429ca2bc5038445a943affected · git
    • 7246d8ed4dcce23f7509949a77be15fa9f0e3d28 and later · before fe09dd288722f1c749b7506c0b3e7841a7d85027affected · git
    • 7246d8ed4dcce23f7509949a77be15fa9f0e3d28 and later · before e09f7bd7273928b4089e6b71f8e992f2b356ca1baffected · git
    • 7246d8ed4dcce23f7509949a77be15fa9f0e3d28 and later · before a48802fb2cd2d1e23651989f8ff4d15e9d5dad54affected · git
    • before 5.0not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.180-16.1.180-1
Debian:13linuxbefore 6.12.100-16.12.100-1
Debian:14linuxbefore 7.1.5-17.1.5-1

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-2026-72502Aug 15, 2026 · tcp: ipv6: clamp default adverting MSS to avoid GSO_BY_FRAGS (0xFFFF)
    30Monitor
  • ← EarlierCVE-2026-74255Aug 15, 2026 · tipc: fix UAF in tipc_l2_send_msg()
    39Monitor
  • Later →CVE-2026-74257Aug 15, 2026 · sockmap: Fix use-after-free in udp_bpf_recvmsg()
    31Monitor

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 Linux17eb9832a10db2f7a80cb429ca2bc5038445a943Vendor (CNA)
Linux Linux9ef44ed6fb0c1db01cfcc3de432a33e719713eb5Vendor (CNA)
Linux Linuxa48802fb2cd2d1e23651989f8ff4d15e9d5dad54Vendor (CNA)
Linux Linuxba5cc05dae8fce237d191c7ea96b1107a791e548Vendor (CNA)
Linux Linuxc05a0ec1cdced622a1a0c7d85679fe02f31033ecVendor (CNA)
Linux Linuxd693c5ed67dabe1ccbf8dcea93075bdc9ffd4ca0Vendor (CNA)
Linux Linuxe09f7bd7273928b4089e6b71f8e992f2b356ca1bVendor (CNA)
Linux Linuxfe09dd288722f1c749b7506c0b3e7841a7d85027Vendor (CNA)
debian:linux6.1.180-1 · Debian:12Package registry (OSV)

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).

Technical details

Attack conditions

  • Someone with local access to the system 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
Local
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:L/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