CVE-2026-120830: Libslirp: libslirp: out-of-bounds heap read in icmp_forward_error() leading to information disclosure
Vulnerability summary
CVE-2026-120830 is a high (CVSS 7.4) Out-of-bounds Read vulnerability in libslirp Debian. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 12.7% of scored vulnerabilities.
Not severe (CVSS 7.4, adjacent network); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Timeline
- 03-11-2026PublishedVulnerability first disclosed.
- 03-11-2026Last modifiedVulnerability information updated.
Description
A flaw was found in libslirp in icmp_forward_error(). When building an ICMP error response, the length of the quoted original IPv4 packet was taken from the IP header without clamping it to the actual buffer length. A truncated or malformed packet could cause an out-of-bounds heap read, leaking host memory into the ICMP error packet returned to a guest or container.
CVSS metrics
3 scores · 3 sources · 1 version- NVDNIST7.4HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
- OSV · DebianEcosystem advisory · calculated7.4HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
EPSS trend
Probability
0.22%
Chance of exploitation in the next 30 days
Percentile
13%
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: adjacent network, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Debian1 product
- libslirpAll versions (No fix recorded)
1 vendor · 1 product
