CVE-2026-18313: CWE-401 Missing Release of Memory after Effective Lifetime in The Tcpdump Group libpcap
Description
CVE-2026-18313 is a medium severity vulnerability in libpcap's rpcapd component where memory allocated for certain client messages is never freed, causing a memory leak. This leak occurs during normal use and can be accelerated by a malicious client sending specific requests. The issue affects libpcap versions from 1.9.0 up to but not including 1.10.7. There is no indication of confidentiality or integrity impact, only availability degradation due to memory exhaustion.
CVSS v3.1
Score 4.3medium
Affected software
The Tcpdump Group
libpcap
Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in libpcap's rpcapd allows memory allocated for RPCAP_MSG_UPDATEFILTER_REQ or RPCAP_MSG_STARTCAP_REQ messages to never be released, resulting in a memory leak. Each such message can allocate up to 65536 bytes that remain unreleased, leading to resource exhaustion over time. A malicious client can exploit this by sending these messages repeatedly to accelerate the leak. The flaw affects versions >=1.9.0 and <1.10.7. The CVSS score is 4.3 (medium severity) with no confidentiality or integrity impact, only availability impact due to resource depletion.
Potential Impact
The vulnerability causes a memory leak in the rpcapd server component of libpcap, which can degrade availability by exhausting memory resources. There is no impact on confidentiality or integrity. A malicious client can increase the rate of memory consumption, potentially leading to denial of service conditions.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch links are provided in the available data. Users should monitor vendor communications for updates and consider limiting exposure of rpcapd services to untrusted clients to reduce risk.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- Tcpdump
- Date Reserved
- 2026-07-29T17:47:46.571Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6a9c688aacd9273b49460eba
Added to database: 09/05/2026, 19:07:54 UTC
Last enriched: 09/15/2026, 01:01:49 UTC
Last updated: 10/19/2026, 18:48:18 UTC
Views: 94
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
External Links
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.