Libsoup: signed to unsigned conversion error leading to stack-based buffer overflow in libsoup ntlm authentication
Noroxi assessment
Priority: Monitor (action score 34/100)
- 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: 0.61% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: libsoup3-doc (AlmaLinux:10) 3.6.5-3.el10_1.9; libsoup (AlmaLinux:8) 2.62.3-13.el8_10; libsoup-devel (AlmaLinux:8) 2.62.3-13.el8_10.
Low priority for now. Upgrade to libsoup3-doc (AlmaLinux:10) 3.6.5-3.el10_1.9; libsoup (AlmaLinux:8) 2.62.3-13.el8_10; libsoup-devel (AlmaLinux:8) 2.62.3-13.el8_10 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 flaw was identified in the NTLM authentication handling of the libsoup HTTP library, used by GNOME and other applications for network communication. When processing extremely long passwords, an internal size calculation can overflow due to improper use of signed integers. This results in incorrect memory allocation on the stack, followed by unsafe memory copying. As a result, applications using libsoup may crash unexpectedly, creating a denial-of-service risk.
- BDU:2026-04957
- ALSA-2026:2182
- ALSA-2026:2215
- ALSA-2026:2216
- openSUSE-SU-2026:10040-1
- openSUSE-SU-2026:10041-1
- openSUSE-SU-2026:20142-1
- openSUSE-SU-2026:20354-1
- RHSA-2026:1948
- RHSA-2026:2005
- RHSA-2026:2006
- RHSA-2026:2007
- RHSA-2026:2008
- RHSA-2026:2049
- RHSA-2026:2182
- RHSA-2026:2214
- RHSA-2026:2215
- RHSA-2026:2216
- RHSA-2026:2396
- RHSA-2026:2402
- Published
- Jan 8, 2026
- Updated
- Jul 15, 2026
- EPSS
- 0.6% · 48th percentile
- CWE
- CWE-121
Report tools
Action score
34
Monitor
Low priority for now.
- CVSS
- 34 / 40 · 8.6 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.6%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · redhat
- 8.6
- 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.
Get told when this record changes
- 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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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.
We use this product, ask for helpAffected 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.
| Vendor | Product | CPE |
|---|---|---|
| enterprise linux | 10.1 | cpe:2.3:redhat:enterprise_linux:10.1 |
| enterprise linux eus | 10.0 | cpe:2.3:redhat:enterprise_linux_eus:10.0 |
| rhel els | 7 | cpe:2.3:redhat:rhel_els:7 |
| enterprise linux | 8 | cpe:2.3:redhat:enterprise_linux:8 |
| rhel aus | 8.2 | cpe:2.3:redhat:rhel_aus:8.2 |
| rhel aus | 8.4 | cpe:2.3:redhat:rhel_aus:8.4 |
| rhel eus long life | 8.4 | cpe:2.3:redhat:rhel_eus_long_life:8.4 |
| rhel aus | 8.6 | cpe:2.3:redhat:rhel_aus:8.6 |
| rhel tus | 8.6 | cpe:2.3:redhat:rhel_tus:8.6 |
| rhel e4s | 8.6 | cpe:2.3:redhat:rhel_e4s:8.6 |
| rhel tus | 8.8 | cpe:2.3:redhat:rhel_tus:8.8 |
| rhel e4s | 8.8 | cpe:2.3:redhat:rhel_e4s:8.8 |
and 7 more
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
- 0:3.6.5-3.el10_1.9 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support
- 0:3.6.5-3.el10_0.14 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 6
- all versionsunknown
Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support
- 0:2.62.2-11.el7_9 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8
- 0:8.10-7 and laternot affected · rpm
- 0:2.62.3-13.el8_10 and laternot affected · rpm
- 0:2.62.3-13.el8_10 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.2 Advanced Update Support
- 0:2.62.3-1.el8_2.8 and laternot affected · rpm
- 0:8.10-7.el8_2.1 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
- 0:2.62.3-2.el8_4.8 and laternot affected · rpm
- 0:8.10-7.el8_4.1 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On
- 0:2.62.3-2.el8_4.8 and laternot affected · rpm
- 0:8.10-7.el8_4.1 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
- 0:2.62.3-2.el8_6.8 and laternot affected · rpm
- 0:8.10-7.el8_6.1 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.6 Telecommunications Update Service
- 0:2.62.3-2.el8_6.8 and laternot affected · rpm
- 0:8.10-7.el8_6.1 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions
- 0:2.62.3-2.el8_6.8 and laternot affected · rpm
- 0:8.10-7.el8_6.1 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service
- 0:2.62.3-3.el8_8.8 and laternot affected · rpm
- 0:8.10-7.el8_8.1 and laternot affected · rpm
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:10 | libsoup3-doc | before 3.6.5-3.el10_1.9 | 3.6.5-3.el10_1.9 |
| AlmaLinux:8 | libsoup | before 2.62.3-13.el8_10 | 2.62.3-13.el8_10 |
| AlmaLinux:8 | libsoup-devel | before 2.62.3-13.el8_10 | 2.62.3-13.el8_10 |
| AlmaLinux:9 | libsoup | before 2.72.0-12.el9_7.5 | 2.72.0-12.el9_7.5 |
| AlmaLinux:9 | libsoup-devel | before 2.72.0-12.el9_7.5 | 2.72.0-12.el9_7.5 |
| Debian:12 | libsoup2.4 | from 0 | — |
| Debian:12 | libsoup3 | from 0 | — |
| Debian:14 | libsoup3 | before 3.8.0-1 | 3.8.0-1 |
| openSUSE:Leap 15.6 | libsoup | before 3.4.4-150600.3.28.1 | 3.4.4-150600.3.28.1 |
| openSUSE:Leap 15.6 | libsoup2 | before 2.74.3-150600.4.19.1 | 2.74.3-150600.4.19.1 |
| openSUSE:Leap 16.0 | libsoup | before 3.6.5-160000.3.1 | 3.6.5-160000.3.1 |
| openSUSE:Leap 16.0 | libsoup2 | before 2.74.3-160000.4.1 | 2.74.3-160000.4.1 |
| openSUSE:Tumbleweed | libsoup | before 3.6.5-11.1 | 3.6.5-11.1 |
| openSUSE:Tumbleweed | libsoup2 | before 2.74.3-14.1 | 2.74.3-14.1 |
| Red Hat:enterprise_linux_eus:10.0 | libsoup3 | before 0:3.6.5-3.el10_0.14 | 0:3.6.5-3.el10_0.14 |
| Red Hat:enterprise_linux_eus:10.0 | libsoup3-debuginfo | before 0:3.6.5-3.el10_0.14 | 0:3.6.5-3.el10_0.14 |
| Red Hat:enterprise_linux_eus:10.0 | libsoup3-debugsource | before 0:3.6.5-3.el10_0.14 | 0:3.6.5-3.el10_0.14 |
| Red Hat:enterprise_linux_eus:10.0 | libsoup3-devel | before 0:3.6.5-3.el10_0.14 | 0:3.6.5-3.el10_0.14 |
| Red Hat:enterprise_linux_eus:10.0 | libsoup3-doc | before 0:3.6.5-3.el10_0.14 | 0:3.6.5-3.el10_0.14 |
| Red Hat:enterprise_linux:10.1 | libsoup3 | before 0:3.6.5-3.el10_1.9 | 0:3.6.5-3.el10_1.9 |
| Red Hat:enterprise_linux:10.1 | libsoup3-debuginfo | before 0:3.6.5-3.el10_1.9 | 0:3.6.5-3.el10_1.9 |
| Red Hat:enterprise_linux:10.1 | libsoup3-debugsource | before 0:3.6.5-3.el10_1.9 | 0:3.6.5-3.el10_1.9 |
| Red Hat:enterprise_linux:10.1 | libsoup3-devel | before 0:3.6.5-3.el10_1.9 | 0:3.6.5-3.el10_1.9 |
| Red Hat:enterprise_linux:10.1 | libsoup3-doc | before 0:3.6.5-3.el10_1.9 | 0:3.6.5-3.el10_1.9 |
+71
Same product
red hat: all recordsOther highest-scoring records for the same primary product.
- CVE-2025-10230Samba: command injection in wins server hook script52Plan
- CVE-2026-4631Cockpit: cockpit: unauthenticated remote code execution due to ssh command-line argument injection42Plan
- CVE-2026-76578Ipa: freeipa: freeipa: unauthenticated ldap client can obtain administrator credentials via the self-managed-token aci39Monitor
Published before and after this one in the same product
- ← EarlierCVE-2025-13193Nov 17, 2025 · Libvirt: information disclosure via world-readable vm snapshots22Monitor
- ← EarlierCVE-2025-14523Dec 11, 2025 · Libsoup: libsoup: duplicate host header handling causes host-parsing discrepancy (first- vs last-value wins)32Monitor
- Later →CVE-2026-0716Jan 13, 2026 · Libsoup: out-of-bounds read in libsoup websocket frame processing19Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| almalinux:libsoup | 2.62.3-13.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:libsoup-devel | 2.62.3-13.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:libsoup3-doc | 3.6.5-3.el10_1.9 · AlmaLinux:10 | Package registry (OSV) |
| debian:libsoup3 | 3.8.0-1 · Debian:14 | Package registry (OSV) |
| opensuse:libsoup | 3.4.4-150600.3.28.1 · openSUSE:Leap 15.6 | Package registry (OSV) |
| opensuse:libsoup2 | 2.74.3-150600.4.19.1 · openSUSE:Leap 15.6 | Package registry (OSV) |
| red hat:libsoup | 0:2.62.3-3.el8_8.8 · Red Hat:rhel_e4s:8.8::baseos | Package registry (OSV) |
| red hat:libsoup-debuginfo | 0:2.62.3-3.el8_8.8 · Red Hat:rhel_e4s:8.8::appstream | Package registry (OSV) |
| red hat:libsoup-debugsource | 0:2.62.3-3.el8_8.8 · Red Hat:rhel_e4s:8.8::appstream | Package registry (OSV) |
| red hat:libsoup-devel | 0:2.62.3-3.el8_8.8 · Red Hat:rhel_e4s:8.8::appstream | Package registry (OSV) |
| red hat:libsoup3 | 0:3.6.5-3.el10_0.14 · Red Hat:enterprise_linux_eus:10.0 | Package registry (OSV) |
| red hat:libsoup3-debuginfo | 0:3.6.5-3.el10_0.14 · Red Hat:enterprise_linux_eus:10.0 | Package registry (OSV) |
| red hat:libsoup3-debugsource | 0:3.6.5-3.el10_0.14 · Red Hat:enterprise_linux_eus:10.0 | Package registry (OSV) |
| red hat:libsoup3-devel | 0:3.6.5-3.el10_0.14 · Red Hat:enterprise_linux_eus:10.0 | Package registry (OSV) |
| red hat:libsoup3-doc | 0:3.6.5-3.el10_0.14 · Red Hat:enterprise_linux_eus:10.0 | Package registry (OSV) |
| red hat:spice-client-win | 0:8.10-7.el8_10 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| red hat:spice-client-win-x64 | 0:8.10-7.el8_10 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| red hat:spice-client-win-x86 | 0:8.10-7.el8_10 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| rocky linux:libsoup | 0:2.62.3-13.el8_10 · Rocky Linux:8 | Package registry (OSV) |
| rocky linux:libsoup3 | 0:3.6.5-3.el10_1.9 · Rocky Linux:10 | Package registry (OSV) |
| rocky linux:spice-client-win | 0:8.10-7.el8_10 · Rocky Linux:8 | Package registry (OSV) |
| suse:libsoup | 2.68.4-150200.4.19.1 · SUSE:Linux Enterprise Micro 5.2 | Package registry (OSV) |
| suse:libsoup | 3.4.4-150600.3.28.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP7 | Package registry (OSV) |
| suse:libsoup2 | 2.74.3-150600.4.19.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP7 | Package 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.
No dated events beyond publication.
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 researchersFinders, 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-2026-176125 days apartLibsoup: stack-based buffer overflow in libsoup multipart response parsingmultipart http response34Monitor
- CVE-2026-43958144 days apartRrdtool: rrdtool: stack buffer overflow allows local code execution or denial of service31Monitor
- CVE-2026-112257284 days apartGimp: gimp: heap out-of-bounds read/write in psd thumbnail loader (load_resource_1033)31Monitor
- CVE-2026-59692182 days apartGstreamer1-plugins-bad-free: gstreamer: dtls certificate subject dn stack buffer overflow in openssl_verify_callback30Monitor
- CVE-2026-16277193 days apartRpcbind: rpcbind: stack buffer overflow in rpcinfo rpcbaddrlist()26Monitor
- CVE-2026-16461194 days apartRpcbind: rpcbind: stack buffer overflow in rpcinfo rpcbdump() short-mode version-list formatting26Monitor
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.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- low · data can be read
- Integrity
- low · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- Low
- Integrity impact
- Low
- Availability impact
- High
Weakness class (CWE)
CWE-121 · Stack-based Buffer OverflowCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/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.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (19 more)Show less
- access.redhat.com/errata/RHSA-2026:2005
- access.redhat.com/errata/RHSA-2026:2006
- access.redhat.com/errata/RHSA-2026:2007
- access.redhat.com/errata/RHSA-2026:2008
- access.redhat.com/errata/RHSA-2026:2049
- access.redhat.com/errata/RHSA-2026:2182
- access.redhat.com/errata/RHSA-2026:2214
- access.redhat.com/errata/RHSA-2026:2215
- access.redhat.com/errata/RHSA-2026:2216
- access.redhat.com/errata/RHSA-2026:2396
- access.redhat.com/errata/RHSA-2026:2402
- access.redhat.com/errata/RHSA-2026:2512
- access.redhat.com/errata/RHSA-2026:2513
- access.redhat.com/errata/RHSA-2026:2514
- access.redhat.com/errata/RHSA-2026:2528
- access.redhat.com/errata/RHSA-2026:2529
- access.redhat.com/errata/RHSA-2026:2628
- access.redhat.com/errata/RHSA-2026:2844
- access.redhat.com/security/cve/CVE-2026-0719
Vendor advisories and official records. Exploit/PoC links are deliberately left out.