How severe is CVE-2011-2691?

CVE-2011-2691 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2011-2691 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2011-2691?

CVE-2011-2691 primarily affects Libpng. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2011-2691?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2011-2691 published?

CVE-2011-2691 was published on 2011-07-17 and last updated on 2026-06-16.

CVE-2011-2691

CVE-2011-2691 is a medium-severity vulnerability in Libpng with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.3
EPSS exploit prediction: 4% (89th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-476
Affected product: Libpng
Published: 2011-07-17
Last modified: 2026-06-16

Description

The png_err 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 makes a function call using a NULL pointer argument instead of an empty-string argument, which allows remote attackers to cause a denial of service (application crash) via a crafted PNG image.

Frequently asked questions

What is CVE-2011-2691?: The png_err 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 makes a function call using a NULL pointer argument instead of an empty-string argument, which allows remote attackers to cause a denial of service (application crash) via a crafted PNG image.
How severe is CVE-2011-2691?: CVE-2011-2691 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2011-2691 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2011-2691?: CVE-2011-2691 primarily affects Libpng. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2011-2691?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2011-2691 published?: CVE-2011-2691 was published on 2011-07-17 and last updated on 2026-06-16.

References

Affected products (4)

cpe:2.3:a:libpng:libpng:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:14:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:5.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:6.0:*:*:*:*:*:*:*

More vulnerabilities in Libpng

CVE-2017-12652 — Critical (CVSS 9.8): libpng before 1.6.32 does not properly check the length of chunks against the user limit.
CVE-2010-1205 — Critical (CVSS 9.8): Buffer overflow in pngpread.c in libpng before 1.2.44 and 1.4.x before 1.4.3, as used in progressive applications,…
CVE-2018-14550 — High (CVSS 8.8): An issue has been found in third-party PNM decoding associated with libpng 1.6.35. It is a stack-based buffer overflow…
CVE-2015-8540 — High (CVSS 8.8): Integer underflow in the png_check_keyword function in pngwutil.c in libpng 0.90 through 0.99, 1.0.x before 1.0.66,…
CVE-2015-0973 — High (CVSS 8.8): Buffer overflow in the png_read_IDAT_data function in pngrutil.c in libpng before 1.5.21 and 1.6.x before 1.6.16 allows…
CVE-2014-9495 — High (CVSS 8.8): Heap-based buffer overflow in the png_combine_row function in libpng before 1.5.21 and 1.6.x before 1.6.16, when…

All CVEs affecting Libpng →

Other CWE-476 (NULL Pointer Dereference) vulnerabilities

CVE-2022-36648 — Critical (CVSS 10.0): The hardware emulation in the of_dpa_cmd_add_l2_flood of rocker device model in QEMU, as used in 7.0.0 and earlier,…
CVE-2020-14500 — Critical (CVSS 10.0): Secomea GateManager all versions prior to 9.2c, An attacker can send a negative value and overwrite arbitrary data.
CVE-2010-2495 — Critical (CVSS 10.0): The pppol2tp_xmit function in drivers/net/pppol2tp.c in the L2TP implementation in the Linux kernel before 2.6.34 does…
CVE-2026-46195 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: smb: client: validate dacloffset before building…
CVE-2026-31657 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: batman-adv: hold claim backbone gateways by…
CVE-2026-31436 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: fix possible wrong descriptor…

Browse all CWE-476 (NULL Pointer Dereference) vulnerabilities →