Linux Kernel: Out-of-Bounds Read (CVE-2026-98969)
Published Last modified Sources: BSI, Msrc Update Guide, CVE.org
What is affected, what to do
Update Linux Kernel to version 5.10.273, Linux Kernel to version 5.15.224, Linux Kernel to version 6.1.191.
- Affected
- Linux Kernel
lt 2.6.13..5.10.273 - Linux Kernel
lt 5.11..5.15.224 - Linux Kernel
lt 5.16..6.1.191 - Linux Kernel
lt 6.2..6.6.160 - Linux Kernel
lt 6.7..6.12.113 - Linux Kernel
lt 6.13..6.18.57 - Linux Kernel
lt 6.19..7.2.11
- Linux Kernel
- Fixed in
- Linux Kernel
5.10.273 - Linux Kernel
5.15.224 - Linux Kernel
6.1.191 - Linux Kernel
6.6.160 - Linux Kernel
6.12.113 - Linux Kernel
6.18.57 - Linux Kernel
7.2.11 - Linux Kernel
7.3
- Linux Kernel
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Metrics
3.3
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: Vendor (CNA), CVSS v3
3.3
CVSS v3
Severity Low on the scale from 0 to 10.
Source: BSI, Msrc Update Guide, CVE.org
0.2 %
EPSS score
Low — model estimates < 1% exploitation likelihood.
Source: FIRST EPSS, percentile 7.3
Show all metrics
- Severity
- Low
Priority (0–325)
The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?
Read in glossary- 46.92 Methodology
Exploit maturity
An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.
Read in glossary- no public PoC known
XIEM Effective CVSS
XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.
Read in glossary- 3.3 Methodology
CVSS v3
CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.
Read in glossary- 3.3
EPSS score
The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.
Read in glossary- 0.2 %
- Low — model estimates < 1% exploitation likelihood.
EPSS percentile
The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.
Read in glossary- 7.3
- Low — this CVE sits in the lower 10% of all CVEs scored today.
KEV status
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- —
- Published
Detection rules
No NEOSEC detection rule is available for this vulnerability yet.
Classification under NIS2 and CRA
Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.
NIS2
NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.
Read in glossary- Handle the vulnerability in regular vulnerability handling under Art. 21(2)(e) NIS2.
CRA
The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.
Read in glossary- From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
ISO/IEC 27001
ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.
Read in glossary- Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.
Description
In the Linux kernel, the following vulnerability has been resolved:
net/sched: em_text: reject unterminated algo before autoload
This is a follow-up to commit 9c572a83037a ("net/sched: fix potential stack infoleak in em_text_dump()"), which zero-initialised the dump-side struct. Sashiko pointed at a pre-existing bug that exposed the change-side input-validation gap open.
em_text_change() casts the raw netlink attribute payload to struct tcf_em_text and passes conf->algo, a 16-byte array with no enforced NUL terminator, to textsearch_prepare(). On the TS_AUTOLOAD retry textsearch_prepare() calls request_module("ts_%s", algo); vsnprintf() walks %s until it finds a NUL, so an algo[] with no NUL reads past the array into the adjacent struct fields and payload and feeds those bytes to the usermode helper command line. This is an out-of-bounds read and a kernel memory disclosure.
Reject the attribute when no NUL exists within TC_EM_TEXT_ALGOSIZ bytes, matching the check xt_string has had since 3ab720881b6e.
Conditions to recreate the bug:
- CAP_NET_ADMIN on the target netns (namespace-local via unshare -Urn is enough)
- install clsact on an interface, then add a basic filter with one text ematch whose algo[] is 16 bytes with no NUL (e.g. "A"*16) and pattern_len at least 1
- the add fails with -ENOENT and the kernel invokes modprobe with a module name made of "ts_" plus the 16 bytes and the adjacent payload
Source: BSI CSAF, BSI WID Portal, Microsoft Security Update Guide, cvelistv5, NVD (NIST)
Affected products
The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.
| Affected versions | Fixed in | ||
|---|---|---|---|
| Linux | Linux |
|
|
Vendors and products
References & sources
- git.kernel.orgstable/c/00bcc303000bac524d62eed054d77372b38ace0f
- git.kernel.orgstable/c/22182f91c6703af6e9832cffe6d22b381031cb5a
- git.kernel.orgstable/c/85e5512369d4fe6e5f2c43712d9f9e01d4ae8437
- git.kernel.orgstable/c/b627c6ba20be20334338229b4820baacb9d96826
- git.kernel.orgstable/c/c9728fcf2e7fb4a7a8d08ebd9524c3b02ae1a021
- git.kernel.orgstable/c/64153f1dd14dabfd4e79bf506bb5b5d66f7b42eb
- git.kernel.orgstable/c/b4da5c85cd701066ff429727fb61b84bde8bcce2
- git.kernel.orgstable/c/b62fb105961b677418cbc0a0a8837a41735729ec
Changes to this CVE
Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).
Record modifiedLinux
Show 4 original changes
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/98xxx/CVE-2026-98969.json">CVE-2026-98969</a>Reference added —https://git.kernel.org/stable/c/64153f1dd14dabfd4e79bf506bb5b5d66f7b42ebReference added —https://git.kernel.org/stable/c/b4da5c85cd701066ff429727fb61b84bde8bcce2Reference added —https://git.kernel.org/stable/c/b62fb105961b677418cbc0a0a8837a41735729ecSource identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
ReceivedLinux
Description added or changed
New references:- https://git.kernel.org/stable/c/00bcc303000bac524d62eed054d77372b38ace0f
- https://git.kernel.org/stable/c/22182f91c6703af6e9832cffe6d22b381031cb5a
- https://git.kernel.org/stable/c/85e5512369d4fe6e5f2c43712d9f9e01d4ae8437
- https://git.kernel.org/stable/c/b627c6ba20be20334338229b4820baacb9d96826
and 1 more reference
Show 7 original changes
Individual changes of this event as published by NVD Type Action Before After Description added —In the Linux kernel, the following vulnerability has been resolved: net/sched: em_text: reject unterminated algo before autoload This is a follow-up to commit 9c572a83037a ("net/sched: fix potential stack infoleak in em_text_dump()"), which zero-initialised the dump-side struct. Sashiko pointed at a pre-existing bug that exposed the change-side input-validation gap open. em_text_change() casts the raw netlink attribute payload to struct tcf_em_text and passes conf->algo, a 16-byte array with no enforced NUL terminator, to textsearch_prepare(). On the TS_AUTOLOAD retry textsearch_prepare() calls request_module("ts_%s", algo); vsnprintf() walks %s until it finds a NUL, so an algo[] with no NUL reads past the array into the adjacent struct fields and payload and feeds those bytes to the usermode helper command line. This is an out-of-bounds read and a kernel memory disclosure. Reject the attribute when no NUL exists within TC_EM_TEXT_ALGOSIZ bytes, matching the check xt_string has had since 3ab720881b6e. Conditions to recreate the bug: - CAP_NET_ADMIN on the target netns (namespace-local via unshare -Urn is enough) - install clsact on an interface, then add a basic filter with one text ematch whose algo[] is 16 bytes with no NUL (e.g. "A"*16) and pattern_len at least 1 - the add fails with -ENOENT and the kernel invokes modprobe with a module name made of "ts_" plus the 16 bytes and the adjacent payloadAffected versions (publisher) added —New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/98xxx/CVE-2026-98969.json">CVE-2026-98969</a>Reference added —https://git.kernel.org/stable/c/00bcc303000bac524d62eed054d77372b38ace0fReference added —https://git.kernel.org/stable/c/22182f91c6703af6e9832cffe6d22b381031cb5aReference added —https://git.kernel.org/stable/c/85e5512369d4fe6e5f2c43712d9f9e01d4ae8437Reference added —https://git.kernel.org/stable/c/b627c6ba20be20334338229b4820baacb9d96826Reference added —https://git.kernel.org/stable/c/c9728fcf2e7fb4a7a8d08ebd9524c3b02ae1a021Source identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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<a href="https://intel.neosec.eu/en/cve/CVE-2026-98969"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-98969.svg?lang=en" alt="CVE-2026-98969 – NEOSEC Intel" height="20"></a>