CVE-2026-44601: Tor before 0.4.9.7, when circuit queue memory pressure exists, can experience a client crash because of a doub

Q: How do I fix CVE-2026-44601?

tor: upgrade to 0.4.9.7. Exact commands for each OS are on this page.

Q: Is CVE-2026-44601 being exploited?

CVE-2026-44601 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-44601 affect?

CVE-2026-44601 affects tor. Severity is low (CVSS 3.7). Tor before 0.4.9.7, when circuit queue memory pressure exists, can experience a client crash because of a double close of a circuit, aka TROVE-2026-009.

Q: How urgent is CVE-2026-44601?

Priority 25/100. Remotely exploitable, no login, no user action

Routine

LOW 3.7REMOTEUPGRADE

CVE-2026-44601 is a low-severity flaw (CVSS 3.7) affecting tor. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Tor before 0.4.9.7, when circuit queue memory pressure exists, can experience a client crash because of a double close of a circuit, aka TROVE-2026-009.

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	3.7 (Low)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 73%)
CISA exploited list	No
Weakness	CWE-837
Published	2026-05-07
Last modified	2026-10-26

Publisher (CNA): MITRE · Vendor: torproject

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

Am I affected?

Timeline

2026-05-07 04:16 UTCPublished CVE record published
2026-10-26 19:10 UTCUpdated Record last modified

torproject tor UPGRADE

Affected: < 0.4.9.7

Fixed in: 0.4.9.7

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 0.4.9.7 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade tor

Note

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

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-2026-44601?

tor: upgrade to 0.4.9.7. Exact commands for each OS are on this page.

Is CVE-2026-44601 being exploited?

CVE-2026-44601 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-2026-44601 affect?

CVE-2026-44601 affects tor. Severity is low (CVSS 3.7). Tor before 0.4.9.7, when circuit queue memory pressure exists, can experience a client crash because of a double close of a circuit, aka TROVE-2026-009.

How urgent is CVE-2026-44601?

Priority 25/100. Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-44603 LOW 3.7 UPGRADE Tor before 0.4.9.7 has an out-of-bounds read by one byte via a malformed BEGIN cell, aka TROVE-2026-007.
CVE-2026-44597 LOW 3.7 UPGRADE Tor before 0.4.9.7 has an out-of-bounds read when an END, a TRUNCATE, or a TRUNCATED cell lacks a reason in it
CVE-2026-44600 LOW 3.7 UPGRADE Tor before 0.4.9.7 mishandles accounting of the conflux out-of-order queue during the clearing of a queue, aka
CVE-2026-44602 LOW 3.7 UPGRADE Tor before 0.4.9.7 has a NULL pointer dereference when a CERT cell is received out of order, aka TROVE-2026-00
CVE-2026-44599 LOW 3.7 UPGRADE Tor before 0.4.9.7 can attempt or accept BEGIN_DIR via conflux legs, aka TROVE-2026-008.

References

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