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CVE.org (no NVD analysis yet)· CNA redhat

CVE-2026-107161: Cyrus-sasl: heap buffer overflow in cyrus-sasl add_to_challenge() allows malicious server to crash or compromise digest-md5 clients

Noroxi assessment

Priority: Monitor (action score 30/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.37% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. Special conditions such as timing or configuration are required.
  • Fixed version: azl3 cyrus-sasl 2.1.28-8 on Azure Linux 3.0 Release Notes; azl3 cyrus-sasl-bootstrap 2.1.28-8 on Azure Linux 3.0 Release Notes.

Low priority for now. Upgrade to azl3 cyrus-sasl 2.1.28-8 on Azure Linux 3.0 Release Notes; azl3 cyrus-sasl-bootstrap 2.1.28-8 on Azure Linux 3.0 Release Notes or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A heap-based buffer overflow flaw was found in Cyrus SASL. The add_to_challenge() function in the DIGEST-MD5 plugin computes the size of the buffer needed for a challenge/response field before DIGEST-MD5 quoting is applied, but does not recompute that size when quoting (escaping special characters) makes the value longer. The under-sized buffer is then passed to strcat(), causing a heap-based out-of-bounds write whose size depends on attacker-controlled input. A malicious or on-path DIGEST-MD5 (or HTTP Digest) server can trigger this flaw in a connecting client by supplying a crafted challenge field, such as realm or nonce, most likely resulting in a crash of the client application.

HighCVSS 7.5 · v3.1—No exploit Fix available
Published
Oct 7, 2026
Updated
Nov 6, 2026
EPSS
0.3% · 31th percentile

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · redhat
7.5
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.

  • Red Hat Red Hat Enterprise Linux 10

    • all versionsaffected

  • Red Hat Red Hat Enterprise Linux 6

    • all versionsunknown

  • Red Hat Red Hat Enterprise Linux 7

    • all versionsaffected

  • Red Hat Red Hat Enterprise Linux 8

    • all versionsaffected

  • Red Hat Red Hat Enterprise Linux 9

    • all versionsaffected

  • Red Hat Red Hat Hardened Images

    • all versionsaffected

  • Red Hat Red Hat OpenShift AI (RHOAI)

    • all versionsunknown
    • all versionsunknown
    • all versionsunknown
    • all versionsunknown
    • all versionsunknown
    • all versionsunknown
    • all versionsunknown
    • all versionsunknown
    • all versionsunknown
    • all versionsunknown

  • Red Hat Red Hat OpenShift Container Platform 4

    • all versionsunknown
    • all versionsunknown

  • Red Hat Red Hat OpenShift Container Platform 5

    • all versionsunknown

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12cyrus-sasl2before 2.1.28+dfsg-10+deb12u12.1.28+dfsg-10+deb12u1
Debian:13cyrus-sasl2from 0—
Debian:14cyrus-sasl2before 2.1.28+dfsg1-122.1.28+dfsg1-12
openSUSE:Leap 16.0cyrus-saslbefore 2.1.28-160000.4.12.1.28-160000.4.1
openSUSE:Leap 16.0cyrus-sasl-bdbbefore 2.1.28-160000.4.12.1.28-160000.4.1
openSUSE:Leap 16.0cyrus-sasl-saslauthdbefore 2.1.28-160000.4.12.1.28-160000.4.1
openSUSE:Leap 16.0cyrus-sasl-saslauthd-bdbbefore 2.1.28-160000.4.12.1.28-160000.4.1
openSUSE:Tumbleweedcyrus-saslbefore 2.1.28-13.12.1.28-13.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOScyrus-sasl-bdbbefore 2.1.27-150300.4.9.12.1.27-150300.4.9.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOScyrus-sasl-saslauthdbefore 2.1.27-150300.4.9.12.1.27-150300.4.9.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOScyrus-sasl-saslauthd-bdbbefore 2.1.27-150300.4.9.12.1.27-150300.4.9.1
SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOScyrus-sasl-bdbbefore 2.1.28-150500.3.12.12.1.28-150500.3.12.1
SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOScyrus-sasl-saslauthdbefore 2.1.28-150500.3.12.12.1.28-150500.3.12.1
SUSE:Linux Enterprise Micro 5.3cyrus-saslbefore 2.1.27-150300.4.9.12.1.27-150300.4.9.1
SUSE:Linux Enterprise Micro 5.5cyrus-saslbefore 2.1.28-150500.3.12.12.1.28-150500.3.12.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7cyrus-saslbefore 2.1.28-150600.7.17.12.1.28-150600.7.17.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7cyrus-sasl-saslauthdbefore 2.1.28-150600.7.17.12.1.28-150600.7.17.1
SUSE:Linux Enterprise Module for Legacy 15 SP7cyrus-sasl-bdbbefore 2.1.28-150600.7.17.12.1.28-150600.7.17.1
SUSE:Linux Enterprise Module for Legacy 15 SP7cyrus-sasl-saslauthd-bdbbefore 2.1.28-150600.7.17.12.1.28-150600.7.17.1
SUSE:Linux Enterprise Server 12 SP5-LTSScyrus-saslbefore 2.1.26-14.10.12.1.26-14.10.1
SUSE:Linux Enterprise Server 12 SP5-LTSScyrus-sasl-saslauthdbefore 2.1.26-14.10.12.1.26-14.10.1
SUSE:Linux Enterprise Server 15 SP5-LTSScyrus-sasl-saslauthd-bdbbefore 2.1.28-150500.3.12.12.1.28-150500.3.12.1
SUSE:Linux Enterprise Server 16.0cyrus-saslbefore 2.1.28-160000.4.12.1.28-160000.4.1
SUSE:Linux Enterprise Server 16.0cyrus-sasl-saslauthdbefore 2.1.28-160000.4.12.1.28-160000.4.1

+1

Same product

red hat: all records

Other highest-scoring records for the same primary product.

  • CVE-2025-10230Samba: command injection in wins server hook script
    52Plan
  • CVE-2026-4631Cockpit: cockpit: unauthenticated remote code execution due to ssh command-line argument injection
    44Plan
  • CVE-2026-76578Ipa: freeipa: freeipa: unauthenticated ldap client can obtain administrator credentials via the self-managed-token aci
    39Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-106066Oct 7, 2026 · Gimp: gimp: heap buffer overflow in raw data export on oversized image dimensions
    25Monitor
  • ← EarlierCVE-2026-106067Oct 7, 2026 · Gimp: gimp: heap buffer overflow in hot color filter on oversized image
    25Monitor
  • Later →CVE-2026-107466Oct 8, 2026 · Flatpak-builder: local file exfiltration via `file
    24Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
azl3 cyrus-sasl 2.1.28-8 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 cyrus-sasl-bootstrap 2.1.28-8 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
debian:cyrus-sasl22.1.28+dfsg-10+deb12u1 · Debian:12Package registry (OSV)
debian:cyrus-sasl22.1.28+dfsg1-12 · Debian:14Package registry (OSV)
opensuse:cyrus-sasl2.1.28-13.1 · openSUSE:TumbleweedPackage registry (OSV)
opensuse:cyrus-sasl-bdb2.1.28-160000.4.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:cyrus-sasl-saslauthd2.1.28-160000.4.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:cyrus-sasl-saslauthd-bdb2.1.28-160000.4.1 · openSUSE:Leap 16.0Package registry (OSV)
suse:cyrus-sasl2.1.26-14.10.1 · SUSE:Linux Enterprise Server 12 SP5-LTSSPackage registry (OSV)
suse:cyrus-sasl2.1.28-160000.4.1 · SUSE:Linux Enterprise Server 16.0Package registry (OSV)
suse:cyrus-sasl-bdb2.1.27-150300.4.9.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSPackage registry (OSV)
suse:cyrus-sasl-saslauthd2.1.26-14.10.1 · SUSE:Linux Enterprise Server 12 SP5-LTSSPackage registry (OSV)
suse:cyrus-sasl-saslauthd2.1.28-160000.4.1 · SUSE:Linux Enterprise Server 16.0Package registry (OSV)
suse:cyrus-sasl-saslauthd-bdb2.1.27-150300.4.9.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSPackage registry (OSV)

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.

  1. Published
  2. Fix recorded+4 d
  3. TodayNov 11, 2026+34 d
EPSS, last 120 days

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 researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-52720114 days apartGstreamer1-plugins-bad-free: gstreamer: heap buffer overflow via crafted vnc server rectangle in librfb
    35Monitor
  • CVE-2026-12199729 days apartGdb: gdbserver: heap buffer overflow in cmd_qtdpsrc via qtdpsrc declared/actual length mismatch
    32Monitor
  • CVE-2026-8166533 days apartCorosync: corosync: heap-based buffer overflow in totempg assembly buffer during fragmented message reassembly
    30Monitor
  • CVE-2026-12912100 days apartLibtiff: libtiff: heap-based buffer overflow via crafted pixarlog-compressed tiff image
    29Monitor
  • CVE-2026-3195110 days apartQemu-kvm: virtio-snd: heap buffer overflow in virtio_snd_pcm_in_cb (incomplete fix for cve-2024-7730)
    29Monitor
  • CVE-2026-1032427 days apartRpm: heap-based buffer overflow write in hex2binv() via a mistyped rpmtag_filesignatures header tag
    28Monitor

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.
  • A user must open a link or visit a page.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-122 · Heap-based Buffer Overflow

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

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.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓
  2. SSVC exploitation— → none
  3. Exploit maturity— → none

For records you follow, these changes also arrive as notifications. →

References

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records