# CVE-2026-93203: batman-adv: bla: avoid CRC corruption due to parallel claim add CVE-2026-93203 is fixed in 37 products on 1 platform, first by DEBIAN-CVE-2026-93203, released September 23, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-93203 - Priority: High - CVSS: 7.1 (Moderate) - EPSS: 0.0034 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Sep 17, 2026 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-93203 ## Description In the Linux kernel, the following vulnerability has been resolved: batman-adv: bla: avoid CRC corruption due to parallel claim add batadv_bla_add_claim() is used to add claims and modify the backbone of claims for CLAIM frames from remote backbones and local packets. When it handles a claim, it needs to either * add the new claim's CRC to the backbone CRC * remove the already existing claim's CRC from the old backbone and add it to the new backbone But when the "new" claim code was running in parallel to the "change backbone" code, it can happen that the CRC was invalid because the backbone_gw of the claim was changed twice in the "new" claim code path: * CPU0 creates the claim for gateway A and publishes it in the claim hash. The crc16 of the address has not yet been added to A's crc at this point. * CPU1 processes a claim frame of gateway B for the same client, finds the just published claim, and performs the ownership change: it switches the pointer to B, removes the crc16 from A's crc - which never contained it - and adds it to B's crc. * CPU0 continues behind the creation branch, unconditionally switches the pointer back to A without compensating B's crc (its remove_crc is false for the creation path), and finally adds the crc16 to A's crc The CRC is then wrong for both: * claim belongs to A: but CRC is not part of backbone A's CRC * claim doesn't belong to B: CRC is still part of backbone B's CRC This wrong CRC is never recomputated from the stored claims. For local backbone claims, this can also not recovered using syncs. To avoid this, split the functionality in clear separate parts: * new claim which always adds claim CRC to the backbone CRC (but never changes the already set backbone_gw of the claim back) * update of existing claim which automatically changes the backbone_gw entry and only updates both backbone CRCs when there was an actual change ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | kernel-uek ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-core ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-core ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-core ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-core ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-devel ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-devel ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-core ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-core ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-deprecated ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-deprecated ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-desktop ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-desktop ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-extra ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-extra ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-extra-netfilter ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-extra-netfilter ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-usb ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-usb ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-wireless ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-wireless ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-devel ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-devel ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-doc ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-doc ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-core ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-core ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-deprecated ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-deprecated ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-desktop ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-desktop ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-extra ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-extra ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-extra-netfilter ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-extra-netfilter ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-usb ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-usb ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-wireless ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-wireless ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-tools ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-tools ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-core ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-core ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-devel ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-devel ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-core ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-core ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-deprecated ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-deprecated ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-desktop ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-desktop ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-extra ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-extra ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-extra-netfilter ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-extra-netfilter ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-usb ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-usb ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-wireless ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-wireless ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | linux Debian 12.15 (bookworm) | 6.1.190-1 | [DEBIAN-CVE-2026-93203](https://patchblox.com/security/data/fix/linux/debian-cve-2026-93203.md) | Sep 23, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.111-1 | [DEBIAN-CVE-2026-93203](https://patchblox.com/security/data/fix/linux/debian-cve-2026-93203.md) | Sep 23, 2026 | | Linux | linux Debian 14 | 7.2.6-1 | [DEBIAN-CVE-2026-93203](https://patchblox.com/security/data/fix/linux/debian-cve-2026-93203.md) | Sep 23, 2026 | | Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.111-1~deb12u1 | [DEBIAN-CVE-2026-93203](https://patchblox.com/security/data/fix/linux/debian-cve-2026-93203.md) | Sep 23, 2026 | --- Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.