CVE-2026-115449
Libslirp: libslirp: icmp echo reply length desynchronization leaks host ip to guest
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Libslirp: libslirp: icmp echo reply length desynchronization leaks host ip to guest
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.
- Record
CVE-2026-115449- CVSS 3.1
- 3.5 Low
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N - Weakness
- CWE-200
- Updated
- 2026-11-06
EUVDEUVD-2026-108518
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.
- Record
EUVD-2026-108518- CVSS 3.1
- 3.5 Low
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N - Updated
- 2026-11-06
GitHub AdvisoriesGHSA-pg96-xmqg-mmpv
A flaw was found in libslirp. When handling ICMP echo requests, the reply length is not updated...
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.
- Record
GHSA-pg96-xmqg-mmpv- CVSS 3.1
- 3.5 Low
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N - Weakness
- CWE-200
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-115449- CVSS 3.1
- 3.5 Low
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N - Weakness
- CWE-200
- Updated
- 2026-11-06
OSVDEBIAN-CVE-2026-115449
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.
- Record
DEBIAN-CVE-2026-115449- CVSS 3.1
- 3.5 Low
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N - Updated
- 2026-11-07
OSVUBUNTU-CVE-2026-115449
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.
- Record
UBUNTU-CVE-2026-115449- CVSS 3.1
- 3.5 Low
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N - Updated
- 2026-11-02
OSVAZL-111020No score
CVE-2026-115449 affecting package libslirp for versions less than 4.9.6-1
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.
- Record
AZL-111020- Updated
- 2026-11-07
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
libslirpAzure Linux:3 | before 4.9.6-1 | 4.9.6-1 |
libslirpDebian:12 | All versions, plus listed versions 4.7.0-14.8.0-14.9.1-14.9.2-14.9.3-14.9.4-14.9.5-1 | None known |
libslirpDebian:13 | All versions, plus listed versions 4.8.0-14.8.0-1+deb13u14.9.1-14.9.2-14.9.3-14.9.4-14.9.5-1 | None known |
libslirpDebian:14 | All versions, plus listed versions 4.8.0-14.9.1-14.9.2-14.9.3-14.9.4-14.9.5-1 | None known |
libslirpUbuntu:20.04:LTS | All versions, plus listed versions 4.0.0-14.0.0-24.1.0-14.1.0-24.1.0-2ubuntu14.1.0-2ubuntu24.1.0-2ubuntu2.14.1.0-2ubuntu2.2 | None known |
libslirpUbuntu:22.04:LTS | All versions, plus listed versions 4.4.0-1build14.6.1-14.6.1-1build14.6.1-1ubuntu0.2 | None known |
libslirpUbuntu:24.04:LTS | All versions, plus listed versions 4.7.0-1ubuntu14.7.0-1ubuntu24.7.0-1ubuntu34.7.0-1ubuntu3.1 | None known |
libslirpUbuntu:26.10 | All versions, plus listed versions 4.9.1-1ubuntu14.9.3-1ubuntu1 | None known |
libslirpUbuntu:26.04:LTS | All versions, plus listed versions 4.8.0-1ubuntu14.9.1-1ubuntu14.9.1-1ubuntu1.1 | None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | EUVD, NVD, OSV | |
| facts | CVE List | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-115449 is a low vulnerability (CVSS 3.5) in Red Hat Enterprise Linux 10, published October 22, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.24%, the 15th percentile. Fixed in libslirp 4.9.6-1.