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Impact of Linux Kernel vulnerabilities on B&R products

HIGH
CVSS 7.8
Date 2026-06-23T06:00:00+00:00
Source cisa-csaf
Published by CISA

// Description

B&R is aware of publicly reported vulnerabilities affecting the Linux kernel versions shipped with the products listed as affected in the advisory. Successful local exploitation of these vulnerabilities could allow an attacker to escalate privileges on the affected system. Public proof-of-concept exploits are available for the vulnerabilities described herein. At the time of publication of this advisory, B&R had no evidence of active exploitation targeting B&R products.

// Vulnerabilities (5)

CVE ID CVSS Score Severity Description
CVE-2026-46333 7.1 high
CVE-2026-46333. In the Linux kernel, the following vulnerability has been resolved: ptrace: slightly saner 'get_dumpable()' logic The 'dumpability' of a task is fundamentally about the memory image of the task - the concept comes from whether it can core dump or not - and makes no sense when you don't have an associated mm. And almost all users do in fact use it only for the case where the task has a mm pointer. But we have one odd special case: ptrace_may_access() uses 'dumpable' to check various other things entirely independently of the MM (typically explicitly using flags like PTRACE_MODE_READ_FSCREDS). Including for threads that no longer have a VM (and maybe never did, like most kernel threads). It's not what this flag was designed for, but it is what it is. The ptrace code does check that the uid/gid matches, so you do have to be uid-0 to see kernel thread details, but this means that the traditional "drop capabilities" model doesn't make any difference for this all. Make it all make a *bit* more sense by saying that if you don't have a MM pointer, we'll use a cached "last dumpability" flag if the thread ever had a MM (it will be zero for kernel threads since it is never set), and require a proper CAP_SYS_PTRACE capability to override.
CVE-2026-43494 7.8 high
CVE-2026-43494. In the Linux kernel, the following vulnerability has been resolved: net/rds: reset op_nents when zerocopy page pin fails When iov_iter_get_pages2() fails in rds_message_zcopy_from_user(), the pinned pages are released with put_page(), and rm->data.op_mmp_znotifier is cleared. But we fail to properly clear rm->data.op_nents. Later when rds_message_purge() is called from rds_sendmsg() the cleanup loop iterates over the incorrectly non zero number of op_nents and frees them again. Fix this by properly resetting op_nents when it should be in rds_message_zcopy_from_user().
CVE-2026-46300 7.8 high
CVE-2026-46300. In the Linux kernel, the following vulnerability has been resolved: net: skbuff: preserve shared-frag marker during coalescing skb_try_coalesce() can attach paged frags from @from to @to. If @from has SKBFL_SHARED_FRAG set, the resulting @to skb can contain the same externally-owned or page-cache-backed frags, but the shared-frag marker is currently lost. That breaks the invariant relied on by later in-place writers. In particular, ESP input checks skb_has_shared_frag() before deciding whether an uncloned nonlinear skb can skip skb_cow_data(). If TCP receive coalescing has moved shared frags into an unmarked skb, ESP can see skb_has_shared_frag() as false and decrypt in place over page-cache backed frags. Propagate SKBFL_SHARED_FRAG when skb_try_coalesce() transfers paged frags. The tailroom copy path does not need the marker because it copies bytes into @to's linear data rather than transferring frag descriptors..
CVE-2026-31431 7.8 high
CVE-2026-31431. CVE‑2026‑31431 (Copy Fail) is a Linux kernel vulnerability that may allow a locally authenticated user or compromised container workload to gain elevated (root) privileges on affected systems. The issue originates in the Linux kernel’s cryptographic subsystem and impacts kernels used by most major Linux distributions released since 2017. Successful exploitation requires local code execution, however, in shared, containerized, or multi‑tenant environments this may increase the security risk
CVE-2026-43284 7.8 high
CVE-2026-43284. In the Linux kernel, the following vulnerability has been resolved: xfrm: esp: avoid in-place decrypt on shared skb frags MSG_SPLICE_PAGES can attach pages from a pipe directly to an skb. TCP marks such skbs with SKBFL_SHARED_FRAG after skb_splice_from_iter(), so later paths that may modify packet data can first make a private copy. The IPv4/IPv6 datagram append paths did not set this flag when splicing pages into UDP skbs. That leaves an ESP-in-UDP packet made from shared pipe pages looking like an ordinary uncloned nonlinear skb. ESP input then takes the no-COW fast path for uncloned skbs without a frag_list and decrypts in place over data that is not owned privately by the skb. Mark IPv4/IPv6 datagram splice frags with SKBFL_SHARED_FRAG, matching TCP. Also make ESP input fall back to skb_cow_data() when the flag is present, so ESP does not decrypt external-ly backed frags in place. Private nonlinear skb frags still use the existing fast path. This intentionally does not change ESP output. In esp_output_head(), the path that appends the ESP trailer to existing skb tailroom without calling skb_cow_data() is not reachable for nonlinear skbs: skb_tailroom() returns zero when skb->data_len is nonzero, while ESP tailen is positive. Thus ESP output will either use the separate destination-frag path or fall back to skb_cow_data().

// Affected Products (5)

Vendor Product Asset Type Purdue Level Firmware
Siemens Unknown plc
L1
--
Siemens Unknown plc
L1
--
Siemens Unknown plc
L1
--
Siemens Unknown plc
L1
--
Siemens Unknown plc
L1
--

// Remediations (12)

Mitigation: Successful exploitation of the vulnerabilities described in this advisory requires local access to t
Successful exploitation of the vulnerabilities described in this advisory requires local access to the affected system with low-privileged user credentials. Customers are strongly advised to enforce strict access control policies on all Linux-based systems, ensuring that interactive access is exclusively granted to authorized and trusted personnel. This includes reviewing and hardening user account permissions and disabling unused accounts. Refer to section “General security recommendations” for further advise on how to keep your system secure.
Patch: For affected products, software updates should be installed upon availability. Product
For affected products, software updates should be installed upon availability. Product Patch version - APROL : APROL-AutoYaST-DVD- V4.4-010.10.260602 Until remediated software versions are available, customers are required to conduct a risk assessment of their affected systems and to implement the mitigation measures and workarounds specified in this advisory.
Workaround: Security researchers have identified and validated the following workarounds to reduce exposure to t
Security researchers have identified and validated the following workarounds to reduce exposure to the vulnerabilities described in this advisory. These measures do not remediate the underlying vulnerabilities but effectively block known attack vectors until patched software versions are deployed. Important: Customers are advised to thoroughly test their systems after applying any of the listed workarounds. B&R has no visibility into customer-specific applications running on the underlying Linux system. It is the customer's responsibility to assess whether the applied workarounds interfere with existing application workloads prior to deployment in production environments. For Debian-based systems within an active support lifecycle, kernel patches addressing CVE-2026-31431 are already available via the official package repositories. Customers are strongly encouraged to apply these updates immediately by executing the following command: sudo apt update && sudo apt upgrade A system reboot is required after the upgrade for the updated kernel to take effect. Temporary Mitigation: If an immediate system update is not feasible, the affected kernel module (algif_aead) can be disabled persistently. Security researchers have confirmed this measure effectively prevents exploitation of CVE-2026-31431. Execute the following commands as root: echo "install algif_aead /bin/false" > /etc/modprobe.d/disable-algif.conf rmmod algif_aead 2>/dev/null || true Impact assessment: Disabling the algif_aead module removes the AEAD socket interface from the kernel cryp-to API. This does not affect dm-crypt/LUKS, kTLS, IPsec/XFRM, OpenSSL, GnuTLS, NSS, or SSH. Applications explicitly configured to use the afalg engine or that directly bind aead, skcipher, or hash sockets via AF_ALG may be affected. To assess exposure prior to applying this workaround, run: lsof | grep AF_ALG
Mitigation: Successful exploitation of the vulnerabilities described in this advisory requires local access to t
Successful exploitation of the vulnerabilities described in this advisory requires local access to the affected system with low-privileged user credentials. Customers are strongly advised to enforce strict access control policies on all Linux-based systems, ensuring that interactive access is exclusively granted to authorized and trusted personnel. This includes reviewing and hardening user account permissions and disabling unused accounts. Refer to section “General security recommendations” for further advise on how to keep your system secure.
Patch: For affected products, software updates should be installed upon availability. Product
For affected products, software updates should be installed upon availability. Product Patch version - APROL : APROL-AutoYaST-DVD- V4.4-010.10.260602 Until remediated software versions are available, customers are required to conduct a risk assessment of their affected systems and to implement the mitigation measures and workarounds specified in this advisory.
Workaround: Security researchers have identified and validated the following workarounds to reduce exposure to t
Security researchers have identified and validated the following workarounds to reduce exposure to the vulnerabilities described in this advisory. These measures do not remediate the underlying vulnerabilities but effectively block known attack vectors until patched software versions are deployed. Important: Customers are advised to thoroughly test their systems after applying any of the listed workarounds. B&R has no visibility into customer-specific applications running on the underlying Linux system. It is the customer's responsibility to assess whether the applied workarounds interfere with existing application workloads prior to deployment in production environments. For Debian-based systems within an active support lifecycle, kernel patches addressing CVE-2026-31431 are already available via the official package repositories. Customers are strongly encouraged to apply these updates immediately by executing the following command: sudo apt update && sudo apt upgrade A system reboot is required after the upgrade for the updated kernel to take effect. Temporary Mitigation: If an immediate system update is not feasible, the affected kernel module (algif_aead) can be disabled persistently. Security researchers have confirmed this measure effectively prevents exploitation of CVE-2026-31431. Execute the following commands as root: echo "install algif_aead /bin/false" > /etc/modprobe.d/disable-algif.conf rmmod algif_aead 2>/dev/null || true Impact assessment: Disabling the algif_aead module removes the AEAD socket interface from the kernel cryp-to API. This does not affect dm-crypt/LUKS, kTLS, IPsec/XFRM, OpenSSL, GnuTLS, NSS, or SSH. Applications explicitly configured to use the afalg engine or that directly bind aead, skcipher, or hash sockets via AF_ALG may be affected. To assess exposure prior to applying this workaround, run: lsof | grep AF_ALG
Patch: The problem is corrected in the following product versions: - Edgenius 3.2.4.1 ABB recommends that
The problem is corrected in the following product versions: - Edgenius 3.2.4.1 ABB recommends that customers apply the update at earliest convenience.
Mitigation: Mitigating factors describe conditions and circumstances that make an attack that exploits the vulne
Mitigating factors describe conditions and circumstances that make an attack that exploits the vulnerability difficult or less likely to succeed. Refer to section General security recommendations for further advise on how to keep your system secure. Recommended mitigation factors - Limit access to ssh or cockpit - By default, no additional lower privilege users are present on Edgenius installations
Mitigation: Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel onl
Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.
Mitigation: Only build and run applications from trusted sources.
Only build and run applications from trusted sources.
Mitigation: Only build and run applications from trusted sources.
Only build and run applications from trusted sources.
Mitigation: Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel onl
Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.

// References