CVE-2026-115449: Libslirp: libslirp: icmp echo reply length desynchronization leaks host ip to guest
Vulnerability summary
CVE-2026-115449 is a low (CVSS 3.5) vulnerability in libslirp. EPSS estimates a 0.24% chance of exploitation in the next 30 days, higher than 15.1% of scored vulnerabilities.
Not severe (CVSS 3.5, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Timeline
- 22-10-2026PublishedVulnerability first disclosed.
- 23-10-2026Last modifiedVulnerability information updated.
Description
A flaw was found in libslirp. When handling ICMP echo requests, the reply length is not updated to match the actual data received from the host. Under specific conditions where the normal ICMP socket is unavailable, this length mismatch causes the host's real IP address to be leaked to the guest in the echo reply, breaking the NAT isolation that user-mode networking is expected to provide.
CVSS metrics
4 scores · 4 sources · 1 version- NVDNIST3.5LowCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N
- OSV · DebianEcosystem advisory · calculated3.5LowCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N
- OSV · UbuntuEcosystem advisory · calculated3.5LowCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N
EPSS trend
Probability
0.24%
Chance of exploitation in the next 30 days
Percentile
15%
Versus all other CVEs
30-day change
Change unavailable
Change unavailable
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Debian1 product
- libslirpAll versions (No fix recorded)
Ubuntu1 product
- libslirpAll versions (No fix recorded)
2 vendors · 2 products
