CVE-2026-100890: Null Dereference (CVSS 5.3)

Description

A flaw has been found in Trusted Domain Project OpenDMARC up to 1.4.2. Affected by this vulnerability is the function opendmarc_spf_ipv6_explode in the library libopendmarc/opendmarc_spf.c of the component SPF Parser. This manipulation of the argument cp causes null pointer dereference. It is possible to initiate the attack remotely. The exploit has been published and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

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CVSS v3.1 Score

5.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS — Exploit Prediction

0.0037

Probability of exploitation

0.29%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-404 CWE-404

CWE-476 CWE-476

References

Other References

https://vuldb.com/cve/CVE-2026-100890 https://vuldb.com/submit/917188 https://vuldb.com/vuln/410840 https://vuldb.com/vuln/410840/cti https://weitongli.com/share/opendmarc-ip6-wild-pointer.html

Frequently Asked Questions

What is CVE-2026-100890? +

A flaw has been found in Trusted Domain Project OpenDMARC up to 1.4.2. Affected by this vulnerability is the function opendmarc_spf_ipv6_explode in the library libopendmarc/opendmarc_spf.c of the component SPF Parser. This manipulation of the argument cp causes null pointer dereference. It is possible to initiate the attack remotely. The exploit has been published and may be used. The vendor was contacted early about this disclosure but did not respond in any way. It has a CVSS v3.1 base score of 5.3 (MEDIUM).

How severe is CVE-2026-100890? +

CVE-2026-100890 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0037, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-100890? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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