CVE-2026-28810: CWE-340 Generation of Predictable Numbers or Identifiers in Erlang OTP
CVE-2026-28810 is a vulnerability in the Erlang/OTP kernel's DNS resolver (inet_res and inet_db modules) that allows DNS cache poisoning due to predictable transaction IDs and lack of source port randomization. The resolver uses a sequential 16-bit transaction ID for UDP queries, which can be predicted by an attacker who observes one query or guesses the next ID. This behavior conflicts with RFC 5452 recommendations and makes DNS cache poisoning practical in untrusted network environments. The vulnerability affects Erlang/OTP versions from OTP 17. 0 up to OTP 28. 4. 2, 27. 3. 4. 10, and 26.
AI Analysis
Technical Summary
The vulnerability CVE-2026-28810 in Erlang/OTP kernel's inet_res and inet_db modules arises from the generation of predictable 16-bit transaction IDs for DNS UDP queries without source port randomization. This predictable sequence allows attackers to perform DNS cache poisoning by forging DNS responses that match the predictable transaction ID. The resolver's design assumes deployment in trusted networks with trusted recursive resolvers, but this assumption was not clearly documented previously. The issue affects OTP versions from 17.0 through 28.4.2 and related kernel versions. No official fix or patch is currently documented, and the vulnerability has a CVSS 4.0 score of 6.3 (medium severity).
Potential Impact
The vulnerability enables DNS cache poisoning attacks by allowing an attacker to predict the transaction ID used in DNS queries, which is critical for response validation. This can lead to forged DNS responses being accepted, potentially redirecting users to malicious sites or disrupting DNS resolution. The impact is limited to environments where the resolver is used in untrusted networks or with untrusted recursive resolvers. There are no known exploits in the wild at this time.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should ensure that the Erlang/OTP built-in DNS resolver (inet_res) is only used in trusted network environments with trusted recursive DNS resolvers, as originally intended. Avoid deploying this resolver in environments where spoofed DNS responses are possible.
CVE-2026-28810: CWE-340 Generation of Predictable Numbers or Identifiers in Erlang OTP
Description
CVE-2026-28810 is a vulnerability in the Erlang/OTP kernel's DNS resolver (inet_res and inet_db modules) that allows DNS cache poisoning due to predictable transaction IDs and lack of source port randomization. The resolver uses a sequential 16-bit transaction ID for UDP queries, which can be predicted by an attacker who observes one query or guesses the next ID. This behavior conflicts with RFC 5452 recommendations and makes DNS cache poisoning practical in untrusted network environments. The vulnerability affects Erlang/OTP versions from OTP 17. 0 up to OTP 28. 4. 2, 27. 3. 4. 10, and 26.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2026-28810 in Erlang/OTP kernel's inet_res and inet_db modules arises from the generation of predictable 16-bit transaction IDs for DNS UDP queries without source port randomization. This predictable sequence allows attackers to perform DNS cache poisoning by forging DNS responses that match the predictable transaction ID. The resolver's design assumes deployment in trusted networks with trusted recursive resolvers, but this assumption was not clearly documented previously. The issue affects OTP versions from 17.0 through 28.4.2 and related kernel versions. No official fix or patch is currently documented, and the vulnerability has a CVSS 4.0 score of 6.3 (medium severity).
Potential Impact
The vulnerability enables DNS cache poisoning attacks by allowing an attacker to predict the transaction ID used in DNS queries, which is critical for response validation. This can lead to forged DNS responses being accepted, potentially redirecting users to malicious sites or disrupting DNS resolution. The impact is limited to environments where the resolver is used in untrusted networks or with untrusted recursive resolvers. There are no known exploits in the wild at this time.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should ensure that the Erlang/OTP built-in DNS resolver (inet_res) is only used in trusted network environments with trusted recursive DNS resolvers, as originally intended. Avoid deploying this resolver in environments where spoofed DNS responses are possible.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- EEF
- Date Reserved
- 2026-03-03T14:40:00.590Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69d4bd49aaed68159afc7f61
Added to database: 4/7/2026, 8:16:09 AM
Last enriched: 4/14/2026, 3:52:20 PM
Last updated: 5/24/2026, 8:55:45 AM
Views: 67
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