Linux: Incorrect Calculation
CVE-2026-45988 is a critical-severity incorrect calculation vulnerability in Linux, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions d61482be4aae1835b78875761206241835a7510e, 7b89868305052b94a91b708c462bc2281fa42a4a, 76cb9a2d252274adfae6e293a292434631a7d472 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.46% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Linux to d61482be4aae1835b78875761206241835a7510e or 7b89868305052b94a91b708c462bc2281fa42a4a or 76cb9a2d252274adfae6e293a292434631a7d472 or f55b383070170e988e4dec28be2af1714d258521, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.6.140 or 6.12.86 or 6.18.27 or 7.0.4, whichever matches your release line, or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 17926a79320afa9b95df6b977b40cca6d8713cea up to, but not including, d61482be4aae1835b78875761206241835a7510e; 17926a79320afa9b95df6b977b40cca6d8713cea up to, but not including, 7b89868305052b94a91b708c462bc2281fa42a4a; 17926a79320afa9b95df6b977b40cca6d8713cea up to, but not including, 76cb9a2d252274adfae6e293a292434631a7d472; 17926a79320afa9b95df6b977b40cca6d8713cea up to, but not including, f55b383070170e988e4dec28be2af1714d258521; 17926a79320afa9b95df6b977b40cca6d8713cea up to, but not including, 0422e7a4883f25101903f3e8105c0808aa5f4ce9; 2.6.22 | d61482be4aae1835b78875761206241835a7510e, 7b89868305052b94a91b708c462bc2281fa42a4a, 76cb9a2d252274adfae6e293a292434631a7d472, f55b383070170e988e4dec28be2af1714d258521, 0422e7a4883f25101903f3e8105c0808aa5f4ce9 |
| Linux | Linux Kernel | 2.6.22 up to, but not including, 6.6.140; 6.7 up to, but not including, 6.12.86; 6.13 up to, but not including, 6.18.27; 6.19 up to, but not including, 7.0.4 | 6.6.140, 6.12.86, 6.18.27, 7.0.4 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.
Official description
In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix re-decryption of RESPONSE packets If a RESPONSE packet gets a temporary failure during processing, it may end up in a partially decrypted state - and then get requeued for a retry. Fix this by just discarding the packet; we will send another CHALLENGE packet and thereby elicit a further response. Similarly, discard an incoming CHALLENGE packet if we get an error whilst generating a RESPONSE; the server will send another CHALLENGE.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incorrect Calculation
The product performs a calculation that generates incorrect or unintended results that are later used in security-critical decisions or resource management.
How developers prevent this class of flaw
- Understand your programming language's underlying representation and how it interacts with numeric calculation. Pay close attention to byte size discrepancies, precision, signed/unsigned distinctions, truncation, conversion and casting between types, not-a-number calculations, and how your language handles numbers that are too large or too small for its underlying representation.
- Perform input validation on any numeric input by ensuring that it is within the expected range. Enforce that the input meets both the minimum and maximum requirements for the expected range.
- Use the appropriate type for the desired action. For example, in C/C++, only use unsigned types for values that could never be negative, such as height, width, or other numbers related to quantity.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/0422e7a4883f25101903f3e8105c0808aa5f4ce9
- git.kernel.org/stable/c/76cb9a2d252274adfae6e293a292434631a7d472
- git.kernel.org/stable/c/7b89868305052b94a91b708c462bc2281fa42a4a
- git.kernel.org/stable/c/d61482be4aae1835b78875761206241835a7510e
- git.kernel.org/stable/c/f55b383070170e988e4dec28be2af1714d258521
Recent Incorrect Calculation vulnerabilities
- 7.8 High severity
- 7.5 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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