Medium

CVE-2025-71128 — erspan: Initialize options_len before referencing options.

In the Linux kernel, the following vulnerability has been resolved: erspan: Initialize options_len before referencing options. The struct ip_tunnel_info has a flexible array member named options that is protected by a counted_by(options_len) attribute. The compiler will use this information to enforce runtime bounds checking deployed by FORTIFY_SOURCE string helpers. As laid out in the GCC documentation, the counter must be initialized before the first reference to the flexible array member. After scanning through the files that use struct ip_tunnel_info and also refer to options or options_len, it appears the normal case is to use the ip_tunnel_info_opts_set() helper. Said helper would initialize options_len properly before copying data into options, however in the GRE ERSPAN code a partial update is done, preventing the use of the helper function. Before this change the handling of ERSPAN traffic in GRE tunnels would cause a kernel panic when the kernel is compiled with GCC 15+ and having FORTIFY_SOURCE configured: memcpy: detected buffer overflow: 4 byte write of buffer size 0 Call Trace: <IRQ> __fortify_panic+0xd/0xf erspan_rcv.cold+0x68/0x83 ? ip_route_input_slow+0x816/0x9d0 gre_rcv+0x1b2/0x1c0 gre_rcv+0x8e/0x100 ? raw_v4_input+0x2a0/0x2b0 ip_protocol_deliver_rcu+0x1ea/0x210 ip_local_deliver_finish+0x86/0x110 ip_local_deliver+0x65/0x110 ? ip_rcv_finish_core+0xd6/0x360 ip_rcv+0x186/0x1a0 Reported-at: https://launchpad.net/bugs/2129580

Published Jan 14, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.3% (30-day exploitation probability)+3
Technical severity (medium)+3

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.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.31%

ahead of 22% of scored CVEs · Oct 14, 2026

Affects

Linux

Linux and 1 more

CVSS base

5.5

Medium · 3 source(s)

Prioritization reference: 7.5 provisional

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)

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).
Apply the fixed version or the patch documented under Remediation.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ bb5e62f2d547c4de6d1b144cbce2373a76c33f18 and < b282b2a9eed848587c1348abdd5d83fa346a2743≥ bb5e62f2d547c4de6d1b144cbce2373a76c33f18 and < 35ddf66c65eff93fff91406756ba273600bf61a3version 6.15	Vulnerable	CVE Program (cve.org) e CISA ADP
Linux	Linux Kernel	≥ 6.15.1 and < 6.18.4version 6.15version 6.19-rc1version 6.19-rc2version 6.19-rc3version 6.19-rc4version 6.19-rc5version 6.19-rc6 and 2 more version 6.19-rc7version 6.19-rc8	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Local

Attack complexity

Low

Privileges required

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

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
7.5	CVSS 3.1	High	3.9	3.6	416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database
7.5	CVSS 3.1	High	—	—	Linux via CVE Program (cve.org) e CISA ADP
5.5	CVSS 3.1	Medium	1.8	3.6	nvd@nist.gov via NIST National Vulnerability Database

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov)

Scoring entities (NIST, CNA, ADP) score independently; each score is shown with its origin. For prioritization we use 7.5 (416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database) as a conservative provisional reference — not a definitive official score.

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.31%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.

endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

2026
Affected products added · linux/linux
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
Fix documented
Oct 13, 2026 · NIST National Vulnerability Database
CVSS changed · 5.5
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Modified
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Jan 14, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

2 on the record

git.kernel.org/stable/c/35ddf66c65eff93fff91406756ba273600bf61a3
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/b282b2a9eed848587c1348abdd5d83fa346a2743
Patch, NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 7h
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 7h
Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 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 CWE classification.
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-2025-71128 is "erspan: Initialize options_len before referencing options.", rated Medium. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.5 describes technical severity. EPSS 0.31% 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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