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Vulnerability record · CVE-2016-6263 · published 7 September 2016

CVE-2016-6263: Gnu libidn out-of-bounds read vulnerability

Gnu · Libidn

The stringprep_utf8_nfkc_normalize function in lib/nfkc.c in libidn before 1.33 allows context-dependent attackers to cause a denial of service (out-of-bounds read and crash) via crafted UTF-8 data.

7.5 CVSS 3.0 High EPSS 3.9% · top 10.1% CWE-125 · Out-of-bounds read
7.5CVSS 3.0 base score, v2 5.0
3.9%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
24References
17 Jun 2026Last modified by NVD

Description

The stringprep_utf8_nfkc_normalize function in lib/nfkc.c in libidn before 1.33 allows context-dependent attackers to cause a denial of service (out-of-bounds read and crash) via crafted UTF-8 data.

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://git.savannah.gnu.org/cgit/libidn.git/commit/?id=1fbee57ef3c72db2206dd87e4162108b2f425555 Issue TrackingPatch
http://lists.opensuse.org/opensuse-updates/2016-08/msg00005.html Third Party Advisory
http://lists.opensuse.org/opensuse-updates/2016-08/msg00098.html Third Party Advisory
http://www.debian.org/security/2016/dsa-3658
http://www.openwall.com/lists/oss-security/2016/07/20/6 Mailing ListThird Party Advisory
http://www.openwall.com/lists/oss-security/2016/07/21/4 Mailing ListThird Party Advisory
http://www.securityfocus.com/bid/92070 Third Party AdvisoryVDB Entry
http://www.ubuntu.com/usn/USN-3068-1 Third Party Advisory
https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.ap
https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.ap
https://lists.gnu.org/archive/html/help-libidn/2016-07/msg00009.html Vendor Advisory
https://security.gentoo.org/glsa/201908-06
http://git.savannah.gnu.org/cgit/libidn.git/commit/?id=1fbee57ef3c72db2206dd87e4162108b2f425555 Issue TrackingPatch
http://lists.opensuse.org/opensuse-updates/2016-08/msg00005.html Third Party Advisory
http://lists.opensuse.org/opensuse-updates/2016-08/msg00098.html Third Party Advisory
http://www.debian.org/security/2016/dsa-3658
http://www.openwall.com/lists/oss-security/2016/07/20/6 Mailing ListThird Party Advisory
http://www.openwall.com/lists/oss-security/2016/07/21/4 Mailing ListThird Party Advisory
http://www.securityfocus.com/bid/92070 Third Party AdvisoryVDB Entry
http://www.ubuntu.com/usn/USN-3068-1 Third Party Advisory
https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.ap
https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.ap
https://lists.gnu.org/archive/html/help-libidn/2016-07/msg00009.html Vendor Advisory
https://security.gentoo.org/glsa/201908-06

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Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2016-6263), CISA KEV, FIRST EPSS (scores of 2026-09-28). This page is refreshed as NVD updates the record.