CVE catalog

CVE-2015-6525

libevent: CVE-2015-6525

Severity: Medium
Published: Aug 24, 2015, 12:00:00 AM UTC
Source: [NVD] · [CVE record]
EPSS: 4.81% · Oct 25, 2026

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.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	libevent	sid	`2.1.13-stable-1`	fixed
Debian	libevent	forky	`2.1.13-stable-1`	fixed
Debian	libevent	trixie	`2.1.12-stable-10`	fixed
Debian	libevent	trixie-security	`2.1.13-stable-1~deb13u1`	fixed
Debian	libevent	bookworm	`2.1.12-stable-8`	fixed
Debian	libevent	bookworm-security	`2.1.12-stable-8+deb12u1`	fixed
Ubuntu	libevent	14.04	`2.0.21-stable-1`	vulnerable
Ubuntu	libevent	14.04	`2.0.21-stable-1ubuntu1`	vulnerable
Ubuntu	libevent	14.04	`2.0.21-stable-1ubuntu1.14.04.1`	fixed

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	libevent	source	sid	`2.0.21-stable-2`	not yet assigned	Not reported	Not reported
Debian	libevent	source	forky	`2.0.21-stable-2`	not yet assigned	Not reported	Not reported
Debian	libevent	source	trixie	`2.0.21-stable-2`	not yet assigned	Not reported	Not reported
Debian	libevent	source	bookworm	`2.0.21-stable-2`	not yet assigned	Not reported	Not reported
Ubuntu	libevent	deb	14.04	`2.0.21-stable-1ubuntu1.14.04.1`	Not reported	UBUNTU-CVE-2015-6525	Not reported

OpenFactory catalog packages

Matching against OpenFactory catalog package versions is in progress.

[Debian 12 (Bookworm)]

[libevent-2.1-7]Unknown
Source package: [libevent]
Details (2)
- 2.1.12-stable-8 · amd64 · bookworm
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · bookworm; dsa · libevent · debian · 12
- 2.1.12-stable-8 · arm64 · bookworm
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · bookworm; dsa · libevent · debian · 12
[libevent-core-2.1-7]Unknown
Source package: [libevent]
Details (2)
- 2.1.12-stable-8 · amd64 · bookworm
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · bookworm; dsa · libevent · debian · 12
- 2.1.12-stable-8 · arm64 · bookworm
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · bookworm; dsa · libevent · debian · 12
[libevent-dev]Unknown
Source package: [libevent]
Details (2)
- 2.1.12-stable-8 · amd64 · bookworm
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · bookworm; dsa · libevent · debian · 12
- 2.1.12-stable-8 · arm64 · bookworm
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · bookworm; dsa · libevent · debian · 12
[libevent-extra-2.1-7]Unknown
Source package: [libevent]
Details (2)
- 2.1.12-stable-8 · amd64 · bookworm
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · bookworm; dsa · libevent · debian · 12
- 2.1.12-stable-8 · arm64 · bookworm
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · bookworm; dsa · libevent · debian · 12
[libevent-openssl-2.1-7]Unknown
Source package: [libevent]
Details (2)
- 2.1.12-stable-8 · amd64 · bookworm
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · bookworm; dsa · libevent · debian · 12
- 2.1.12-stable-8 · arm64 · bookworm
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · bookworm; dsa · libevent · debian · 12
[libevent-pthreads-2.1-7]Unknown
Source package: [libevent]
Details (2)
- 2.1.12-stable-8 · amd64 · bookworm
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · bookworm; dsa · libevent · debian · 12
- 2.1.12-stable-8 · arm64 · bookworm
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · bookworm; dsa · libevent · debian · 12

[Debian 13 (Trixie)]

[libevent-2.1-7t64]Unknown
Source package: [libevent]
Details (3)
- 2.1.12-stable-10+b1 · amd64 · trixie
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · 13
- 2.1.12-stable-10+b1 · arm64 · trixie
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · 13
- 2.1.13-stable-1~deb13u1 · amd64 · trixie-security
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · 13
[libevent-core-2.1-7t64]Unknown
Source package: [libevent]
Details (3)
- 2.1.12-stable-10+b1 · amd64 · trixie
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · 13
- 2.1.12-stable-10+b1 · arm64 · trixie
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · 13
- 2.1.13-stable-1~deb13u1 · amd64 · trixie-security
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · 13
[libevent-dev]Unknown
Source package: [libevent]
Details (3)
- 2.1.12-stable-10+b1 · amd64 · trixie
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · 13
- 2.1.12-stable-10+b1 · arm64 · trixie
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · 13
- 2.1.13-stable-1~deb13u1 · amd64 · trixie-security
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · 13
[libevent-extra-2.1-7t64]Unknown
Source package: [libevent]
Details (3)
- 2.1.12-stable-10+b1 · amd64 · trixie
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · 13
- 2.1.12-stable-10+b1 · arm64 · trixie
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · 13
- 2.1.13-stable-1~deb13u1 · amd64 · trixie-security
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · 13
[libevent-openssl-2.1-7t64]Unknown
Source package: [libevent]
Details (3)
- 2.1.12-stable-10+b1 · amd64 · trixie
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · 13
- 2.1.12-stable-10+b1 · arm64 · trixie
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · 13
- 2.1.13-stable-1~deb13u1 · amd64 · trixie-security
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · 13
[libevent-pthreads-2.1-7t64]Unknown
Source package: [libevent]
Details (3)
- 2.1.12-stable-10+b1 · amd64 · trixie
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · 13
- 2.1.12-stable-10+b1 · arm64 · trixie
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · 13
- 2.1.13-stable-1~deb13u1 · amd64 · trixie-security
  Fixed · Fixed: 2.0.21-stable-2
  dsa · libevent · debian · 13

Observed: Oct 23, 2026, 5:16:03 PM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]