In the Linux kernel, the following vulnerability has been resolved: sctp: avoid NULL dereference when chunk data buffer is missing chunk->skb… (CVE-2025-40240)
In the Linux kernel, the following vulnerability has been resolved: sctp: avoid NULL dereference when chunk data buffer is missing chunk->skb pointer is dereferenced in the if-block where it's supposed to be NULL only. chunk->skb can only be NULL if chunk->head_skb is not. Check for frag_list instead and do it just before replacing chunk->skb. We're sure that otherwise chunk->skb is non-NULL because of outer if() condition.
AI Analysis
Technical Summary
The Linux kernel packages in Red Hat Enterprise Linux 9.4 Extended Update Support contain a vulnerability in the SCTP protocol handling where a NULL pointer dereference can occur if the chunk data buffer is missing (CVE-2025-40240). This is a moderate severity issue that could lead to kernel crashes or denial of service. Red Hat has released a security advisory (RHSA-2026:4899) providing an updated kernel package to fix this issue. The update requires a system reboot to apply the fix.
Potential Impact
The vulnerability can cause a NULL pointer dereference in the kernel SCTP code, potentially leading to a denial of service via kernel crash. No known exploits in the wild have been reported. The impact is rated moderate by Red Hat.
Mitigation Recommendations
A security update is available from Red Hat for Red Hat Enterprise Linux 9.4 Extended Update Support and related variants. Users should apply the updated kernel packages as described in the Red Hat advisory RHSA-2026:4899 and reboot the system to activate the fix. Patch status is confirmed as fixed in this update.
In the Linux kernel, the following vulnerability has been resolved: sctp: avoid NULL dereference when chunk data buffer is missing chunk->skb… (CVE-2025-40240)
Description
In the Linux kernel, the following vulnerability has been resolved: sctp: avoid NULL dereference when chunk data buffer is missing chunk->skb pointer is dereferenced in the if-block where it's supposed to be NULL only. chunk->skb can only be NULL if chunk->head_skb is not. Check for frag_list instead and do it just before replacing chunk->skb. We're sure that otherwise chunk->skb is non-NULL because of outer if() condition.
CVSS v3.1
Score 7.5high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel packages in Red Hat Enterprise Linux 9.4 Extended Update Support contain a vulnerability in the SCTP protocol handling where a NULL pointer dereference can occur if the chunk data buffer is missing (CVE-2025-40240). This is a moderate severity issue that could lead to kernel crashes or denial of service. Red Hat has released a security advisory (RHSA-2026:4899) providing an updated kernel package to fix this issue. The update requires a system reboot to apply the fix.
Potential Impact
The vulnerability can cause a NULL pointer dereference in the kernel SCTP code, potentially leading to a denial of service via kernel crash. No known exploits in the wild have been reported. The impact is rated moderate by Red Hat.
Mitigation Recommendations
A security update is available from Red Hat for Red Hat Enterprise Linux 9.4 Extended Update Support and related variants. Users should apply the updated kernel packages as described in the Red Hat advisory RHSA-2026:4899 and reboot the system to activate the fix. Patch status is confirmed as fixed in this update.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2026:4899
- Cve Count
- 1
- Cvss Version
- 3.1
Threat ID: 6a3da1c14853345fc181e079
Added to database: 06/25/2026, 21:46:41 UTC
Last enriched: 06/25/2026, 21:53:47 UTC
Last updated: 09/10/2026, 19:36:50 UTC
Views: 26
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