CVE-2026-1299
email BytesGenerator header injection due to unquoted newlines
No known exploitation. EPSS puts it in the 45th percentile. A vendor fix is available.
What to do
The vendor has published a fix. Version details are below where the sources state them.
What it is
From the CVE record
The email module, specifically the "BytesGenerator" class, didn’t properly quote newlines for email headers when serializing an email message allowing for header injection when an email is serialized. This is only applicable if using "LiteralHeader" writing headers that don't respect email folding rules, the new behavior will reject the incorrectly folded headers in "BytesGenerator".
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.6% chance of exploitation activity in the next 30 days, which ranks it in the 45th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
5 events over 153 days, from the signal feeds we watch.
- OpenVAS check added
- Patch availablerecord updated
- Publishedweakness classified
Affected products
- Red Hat Enterprise LinuxOperating Systems / linux-distro
- OpenShift Dev SpacesOperating Systems / linux-distro
- OpenShift AIOperating Systems / linux-distro
- Red Hat Ceph StorageOperating Systems / linux-distro
- Red Hat Enterprise Linux AIOperating Systems / linux-distro
- Red Hat Update InfrastructureOperating Systems / linux-distro
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorAV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N
Scored 7.1 by bdu.
How it is reached
- Access Vector NetworkExploitable remotely over the network
- Access Complexity LowNo special conditions required
Impact if exploited
- Confidentiality L
- Integrity H
- Availability NoneNo availability impact
Weaknesses
Sources
References in the record
- github.com/python/cpython/issues/144125&
- access.redhat.com/security/cve/cve-2026-1299
- wiki.astralinux.ru/astra-linux-se17-bulletin-2026-0421SE17&
And 12 more references. See all after sign-in
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