SB2026092163 - Anolis OS update for libevent
Published: September 21, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 vulnerabilities.
1) Out-of-bounds read (CVE-ID: CVE-2026-63383)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an out-of-bounds read in decode_tag_internal() when parsing a malformed fragmented evbuffer tag. A remote attacker can send specially crafted input with more than 5 continuation bytes to cause a denial of service.
The issue is reachable through evtag_unmarshal_header(), and potential higher-level reachability exists via evrpc request parsing.
2) Integer overflow (CVE-ID: CVE-2026-63384)
CWE-ID: CWE-190 - Integer overflow
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to integer truncation in evtag_unmarshal_header() and evtag_unmarshal_string() when parsing crafted wire-encoded length fields. A remote attacker can send specially crafted input with a length value above INT_MAX to cause a denial of service.
The issue is triggered when a wire uint32 length is converted to a signed int, causing negative or truncated values that lead to an oversized wrapped allocation request in downstream string unmarshalling.
Remediation
Install update from vendor's website.