CVE-2026-115505 sahlberg CVE debrief

Who should care

Defenders responsible for systems using libsmb2 versions before 6.3 should assess exposure and potential impact. This includes operators, platform administrators, vulnerability management teams, and security teams. They should prioritize verifying libsmb2 version and system configurations for potential impact and review compensating controls for exposed systems.

Why it matters

libsmb2 before 6.3 is vulnerable to integer overflow attacks in the DCE/RPC NDR decoder, potentially leading to heap corruption and system instability. Defenders should prioritize verifying exposure and assessing the impact on systems using libsmb2 versions before 6.3.

• Potential heap corruption and instability
• Possible denial of service or crashes
• Potential for remote code execution or privilege escalation
• Need for verification of libsmb2 version and system configurations

Technical summary

libsmb2 before 6.3 contains integer overflow vulnerabilities in the DCE/RPC NDR decoder in lib/dcerpc.c that allow heap out-of-bounds reads and writes via crafted NetrShareEnum replies with wrapping actual_count or max_count values. This vulnerability can lead to potential heap corruption and system instability. Defenders should prioritize verifying exposure and assessing the impact of potential heap corruption on systems using libsmb2 versions before 6.3. The CVE record and source item provide details on the integer overflow vulnerabilities.

Defensive priority

Defenders should prioritize verifying exposure and assessing the impact of potential heap corruption on systems using libsmb2 versions before 6.3.

Recommended defensive actions

• Verify libsmb2 version and assess exposure
• Review system configurations for potential impact
• Update libsmb2 to version 6.3 or later if possible
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and source item provide details on the integer overflow vulnerabilities in libsmb2 before 6.3. Limited information is available on potential exploitation or victim impact. Defenders should verify exposure and assess potential impact on systems using libsmb2 versions before 6.3. The vulnerability allows heap out-of-bounds reads and writes via crafted NetrShareEnum replies. No evidence of exploitation has been reported.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.