What is CVE-2011-2501?

CVE-2011-2501 is a medium-severity vulnerability in Libpng, classified under Out-of-bounds Read. CVSS score: 6.5/10. Published 2011-07-17.

How severe is CVE-2011-2501?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Out-of-bounds Read in Libpng

CVE-2011-2501

The png_format_buffer function in pngerror.c in libpng 1.0.x before 1.0.55, 1.2.x before 1.2.45, 1.4.x before 1.4.8, and 1.5.x before 1.5.4 allows remote attackers to cause a denial of service (application crash) via a crafted PNG image that triggers an out-of-bounds read during the copying of error-message data. NOTE: this vulnerability exists because of a CVE-2004-0421 regression. NOTE: this is called an off-by-one error by some sources.

Vulnerability class: Buffer Overflow

Published 2011-07-17 · last modified 2026-06-16.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.035 (88.7th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 89th percentile — 88.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.035 · newest: 0.035 · change: 0.000

Affected products

Libpng
Canonical Ubuntu Linux — versions 8.04, 10.04, 10.10
Debian Linux — versions 5.0, 6.0
Fedoraproject Fedora — versions 14

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

secunia.com/advisories/49660 (Broken Link, third-party-advisory)
secunia.com/advisories/45046 (Broken Link, third-party-advisory)
www.ubuntu.com/usn/USN-1175-1 (vendor-advisory, Third Party Advisory)
libpng.git.sourceforge.net/git/gitweb.cgi
www.mandriva.com/security/advisories (vendor-advisory, Broken Link)
www.securityfocus.com/bid/48474 (VDB Entry, Third Party Advisory, vdb-entry)
bugzilla.redhat.com/show_bug.cgi (Patch, Third Party Advisory, Issue Tracking)
slackware.com/security/viewer.php (vendor-advisory, Patch, Mailing List, Third Party Advisory)
security.gentoo.org/glsa/glsa-201206-15.xml (vendor-advisory, Third Party Advisory)
www.openwall.com/lists/oss-security/2011/06/27/13 (mailing-list, Patch, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2011-2501?: CVE-2011-2501 is a medium-severity vulnerability in Libpng, classified under Out-of-bounds Read. CVSS score: 6.5/10. Published 2011-07-17.
How severe is CVE-2011-2501?: Medium severity. CVSS v3 base score is 6.5 out of 10.