CVE-2026-39806: Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in mtrudel bandit allows unauthenticated

This week

HIGH 7.5REMOTEUPGRADE

CVE-2026-39806 is a high-severity flaw (CVSS 7.5) affecting bandit. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in mtrudel bandit allows unauthenticated remote denial of service via worker process exhaustion. 'Elixir.Bandit.HTTP1.Socket':do_read_chunked_data!/5 in lib/bandit/http1/socket.ex terminates only when the last-chunk line 0\r\n is followed immediately by the empty trailer line \r\n. RFC 9112 §7.1.2 permits zero or more trailer fields between them. When trailers are present, none

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 50%)
CISA exploited list	No
Weakness	CWE-835
Published	2026-05-13
Last modified	2026-10-26

Publisher (CNA): EEF · Vendor: mtrudel

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-13 14:17 UTCPublished CVE record published
2026-10-26 14:10 UTCUpdated Record last modified

mtrudel bandit UPGRADE

Affected: >= 1.6.1 and < 1.11.1

Fixed in: 1.11.1

Safe to downgrade to: a release before 1.6.1

1. Check installed version

apt-cache policy bandit || rpm -q bandit || bandit --version

2. UPGRADE to 1.11.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade bandit

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade bandit

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 1.6.1 (Debian / Ubuntu)

apt-cache madison bandit sudo apt install bandit=<VERSION_BEFORE_1.6.1> sudo apt-mark hold bandit

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list bandit sudo dnf downgrade bandit-<VERSION_BEFORE_1.6.1> sudo dnf versionlock add bandit

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-39806?

bandit: upgrade to 1.11.1. Exact commands for each OS are on this page.

Is CVE-2026-39806 being exploited?

CVE-2026-39806 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-39806 affect?

CVE-2026-39806 affects bandit. Severity is high (CVSS 7.5). Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in mtrudel bandit allows unauthenticated remote denial of service via worker process exhaustion. 'Elixir.Bandit.HTTP1.Socket':do_read_chunked_data!/5 in lib/bandit/http1/

How urgent is CVE-2026-39806?

Priority 49/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-39803 HIGH 7.5 UPGRADE Allocation of Resources Without Limits or Throttling vulnerability in mtrudel bandit allows unauthenticated re

References

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