Trusted Domain Project OpenDMARC opendmarc_policy.c opendmarc_policy_parse_dmarc exceptional condition
A vulnerability has been found in Trusted Domain Project OpenDMARC up to 1.4.2. This affects the function opendmarc_policy_parse_dmarc in the library libopendmarc/opendmarc_policy.c. The manipulation of the argument fo/rf/ri/pct/sp/adkim/aspf/rua/ruf leads to handling of exceptional conditions. Remote exploitation of the attack is possible. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
- Published
- Sep 28, 2026
- Updated
- Sep 28, 2026
- EPSS
- 0.3% · 23th percentile
- CWE
- CWE-755
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Report tools
Action score
22
Monitor
Low priority for now.
- CVSS
- 22 / 40 · 5.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.3%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · VulDB
- 6.9
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (VulDB). Independent of NVD's CPE analysis and usually ahead of it.
Trusted Domain Project OpenDMARC
- 1.4.0, 1.4.1, 1.4.2affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | opendmarc | all versions | — |
Same product
trusted domain project: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-101280Trusted Domain Project OpenDMARC Multi-Record Set opendmarc_policy_query_dmarc authentication spoofing22Monitor
- CVE-2026-101279Trusted Domain Project OpenDMARC opendmarc_policy.c integer overflow22Monitor
- CVE-2026-101017Trusted Domain Project OpenDMARC opendmarc_policy.c strcasecmp exceptional condition22Monitor
- CVE-2026-101015Trusted Domain Project OpenDMARC policy.c improper validation of unsafe equivalence in input22Monitor
- CVE-2026-101014Trusted Domain Project OpenDMARC DMARC Record opendmarc_util.c opendmarc_util_cleanup off-by-one22Monitor
- CVE-2026-100891Trusted Domain Project OpenDMARC Internationalized Domain Name opendmarc_policy.c opendmarc_policy_query_dmarc encoding error22Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- yongzhe_xu (VulDB User)reporter
- VulDB CNA Teamcoordinator
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-1010170 days apartTrusted Domain Project OpenDMARC opendmarc_policy.c strcasecmp exceptional condition22Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-755 · Improper Handling of Exceptional ConditionsCVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- SSVC exploitation— → poc
For records you follow, these changes also arrive as notifications. →
References
- vuldb.com/cve/CVE-2026-101016
- vuldb.com/submit/918242
- vuldb.com/vuln/410886
- vuldb.com/vuln/410886/cti
- xuyongzhe-vt.github.io/share/opendmarc-bad-tag-drops-policy.html
Vendor advisories and official records. Exploit/PoC links are deliberately left out.