CVE-2015-6525 Integer overflow in n/a

What is CVE-2015-6525?

CVE-2015-6525 is a high-severity vulnerability in Debian Debian Linux, published on 24 Aug 2015. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Multiple integer overflows in the evbuffer API in Libevent 2.0.x before 2.0.22 and 2.1.x before 2.1.5-beta allow context-dependent attackers to cause a denial of service or possibly have other unspecified impact via "insanely large inputs" to the (1) evbuffer_add, (2) evbuffer_prepend, (3) evbuffer_expand, (4) exbuffer_reserve_space, or (5) evbuffer_read function, which triggers a heap-based buffer overflow or an infinite loop. NOTE: this identifier was SPLIT from CVE-2014-6272 per ADT3 due to different affected versions.

Weakness: CWE-189

Which versions are affected by CVE-2015-6525?

It affects 2 products.

Products include Debian Debian Linux, Libevent Project Libevent.

How do I fix CVE-2015-6525?

Upgrade to a fixed version.

Is CVE-2015-6525 being exploited?

There is no known exploitation of CVE-2015-6525 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2015-6525, GHSA-xfhg-qx7p-6gx5.