CVE-2026-43078
Description
A flaw was found in the Linux kernel. Specifically, within the crypto: af_alg component, a page reassignment overflow could occur in the af_alg_pull_tsgl function. This vulnerability arises because the original loop was not updated, potentially allowing it to reassign one more page than necessary. This could lead to unexpected system behavior or a denial of service (DoS).
Statement
af_alg_pull_tsgl can reassign one extra page into the destination scatterlist because the reassignment path did not check whether plen is non zero. A local process using AF_ALG crypto sockets can craft buffer and scatterlist state so the function advances the destination index for a zero length fragment, which can overrun the caller allocated dst SG entries. For the CVSS the PR:L is used because triggering requires local code execution through the AF_ALG socket API, but not administrator privileges in typical configurations. The issue is not network reachable because the vulnerable input is a local crypto socket operation. Impact is at least local denial of service via kernel crash. In the paranoid case, the destination scatterlist overwrite is treated as a plausible memory corruption primitive with possible confidentiality and integrity impact.
Mitigation
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.3 | N/A | 7.8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | Low | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Instability
This weakness will generally lead to undefined behavior and therefore crashes. In the case of overflows involving loop index variables, the likelihood of infinite loops is also high.
Integrity
Technical Impact: Modify Memory
If the value in question is important to data (as opposed to flow), simple data corruption has occurred. Also, if the wrap around results in other conditions such as buffer overflows, further memory corruption may occur.
Confidentiality,Availability,Access Control
Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism
This weakness can sometimes trigger buffer overflows which can be used to execute arbitrary code. This is usually outside the scope of a program's implicit security policy.
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