CVE-2015-6525
Multiple integer overflows in the evbuffer API in Libevent 2.0.x before 2.0.22 and 2.1.x before 2...
CVE-2015-6525 is a high vulnerability (CVSS 7.5) in Libevent Project Libevent, published January 6, 2015. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 4.81%, the 91st percentile. Fixed in libevent 2.0.21-stable-2.
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.
Exploit likelihood
What each source reports
NVD Score used
7.5
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.
- Record
CVE-2015-6525- CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-189
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2015-6525- Updated
- 2026-11-02
EUVDEUVD-2015-6464 No score
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.
- Record
EUVD-2015-6464- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-xfhg-qx7p-6gx5 No score
Multiple integer overflows in the evbuffer API in Libevent 2.0.x before 2.0.22 and 2.1.x before 2...
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.
- Record
GHSA-xfhg-qx7p-6gx5- Updated
- 2026-11-02
OSV No score
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.
- Record
CVE-2015-6525- Updated
- 2026-11-02
OSVDEBIAN-CVE-2015-6525 No score
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.
- Record
DEBIAN-CVE-2015-6525- Updated
- 2026-11-02
OSVUBUNTU-CVE-2015-6525 No score
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.
- Record
UBUNTU-CVE-2015-6525- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
libeventDebian:12 |
before 2.0.21-stable-2 | 2.0.21-stable-2 |
libeventDebian:13 |
before 2.0.21-stable-2 | 2.0.21-stable-2 |
libeventDebian:14 |
before 2.0.21-stable-2 | 2.0.21-stable-2 |
libeventDebian:7 |
before 2.0.19-stable-3+deb7u1, plus listed versions 2.0.19-stable-3 |
2.0.19-stable-3+deb7u1 |
libeventUbuntu:14.04:LTS |
before 2.0.21-stable-1ubuntu1.14.04.1, plus listed versions 2.0.21-stable-12.0.21-stable-1ubuntu1 |
2.0.21-stable-1ubuntu1.14.04.1 |
History
| When | Changed | Sources |
|---|---|---|
| 2026-11-03 | aliases | EUVD |
| 2026-11-02 | created | CVE List, GitHub Advisories, NVD, OSV |
References
archives.seul.org/libevent/users/Jan-2015/msg00010.html
debian.org/security/2015/dsa-3119
nvd.nist.gov/vuln/detail/CVE-2015-6525
github.com/advisories/GHSA-xfhg-qx7p-6gx5
security-tracker.debian.org/tracker/CVE-2015-6525
ubuntu.com/security/CVE-2015-6525
ubuntu.com/security/notices/USN-2477-1
cve.org/CVERecord?id=CVE-2015-6525