Skip to content
Noroxi
CVE-2025-13151· NVD / CVE Program· CNA certcc

Stack-based buffer overflow in libtasn1 version: v4.20.0.

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: 1.1% (FIRST EPSS); higher than 66.7% of all records.
  • 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.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: azl3 gnutls 3.8.3-8 on Azure Linux 3.0 3.8.3-8; azl3 libtasn1 4.19.0-2 on Azure Linux 3.0 4.19.0-3; azl3 libtasn1 4.19.0-3 on Azure Linux 3.0 4.19.0-3.

Low priority for now. Upgrade to azl3 gnutls 3.8.3-8 on Azure Linux 3.0 3.8.3-8; azl3 libtasn1 4.19.0-2 on Azure Linux 3.0 4.19.0-3; azl3 libtasn1 4.19.0-3 on Azure Linux 3.0 4.19.0-3 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

Stack-based buffer overflow in libtasn1 version: v4.20.0. The function fails to validate the size of input data resulting in a buffer overflow in asn1_expend_octet_string.

HighCVSS 7.5 · v3.1—No exploit Fix available
Published
Jan 7, 2026
Updated
Jun 17, 2026
EPSS
1.2% · 67th 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 · 1.2%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

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.

Follow CVE-2025-13151

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

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Port scanning: 5 full scans a day (members only)
  • Uptime monitoring: 1 site, instant email when it goes down
  • Verify your domain: subdomains and takeover risk scanned every week
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for gnu records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

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 help

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.

VendorProduct
gnulibtasn1

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • gnu libtasn14.20.0

Versions reported by the vendor

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

  • GnuTLS libtasn1

    • up to and including 4.20.0affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:10libtasn1before 4.20.0-5.el10_24.20.0-5.el10_2
AlmaLinux:10libtasn1-develbefore 4.20.0-5.el10_24.20.0-5.el10_2
AlmaLinux:10libtasn1-toolsbefore 4.20.0-5.el10_24.20.0-5.el10_2
AlmaLinux:8libtasn1before 4.13-6.el8_104.13-6.el8_10
AlmaLinux:8libtasn1-develbefore 4.13-6.el8_104.13-6.el8_10
AlmaLinux:8libtasn1-toolsbefore 4.13-6.el8_104.13-6.el8_10
AlmaLinux:9libtasn1before 4.16.0-10.el9_84.16.0-10.el9_8
AlmaLinux:9libtasn1-develbefore 4.16.0-10.el9_84.16.0-10.el9_8
AlmaLinux:9libtasn1-toolsbefore 4.16.0-10.el9_84.16.0-10.el9_8
Alpine:v3.20libtasn1before 4.21.0-r04.21.0-r0
Debian:12libtasn1-6all versions—
Debian:13libtasn1-6before 4.20.0-2+deb13u14.20.0-2+deb13u1
Debian:14libtasn1-6before 4.21.0-24.21.0-2
openSUSE:Leap 16.0libtasn1before 4.21.0-160000.1.14.21.0-160000.1.1
openSUSE:Tumbleweedlibtasn1before 4.21.0-1.14.21.0-1.1
Red Hat:enterprise_linux:10.2libtasn1before 0:4.20.0-5.el10_20:4.20.0-5.el10_2
Red Hat:enterprise_linux:10.2libtasn1-debuginfobefore 0:4.20.0-5.el10_20:4.20.0-5.el10_2
Red Hat:enterprise_linux:10.2libtasn1-debugsourcebefore 0:4.20.0-5.el10_20:4.20.0-5.el10_2
Red Hat:enterprise_linux:10.2libtasn1-develbefore 0:4.20.0-5.el10_20:4.20.0-5.el10_2
Red Hat:enterprise_linux:10.2libtasn1-toolsbefore 0:4.20.0-5.el10_20:4.20.0-5.el10_2
Red Hat:enterprise_linux:10.2libtasn1-tools-debuginfobefore 0:4.20.0-5.el10_20:4.20.0-5.el10_2
Red Hat:enterprise_linux:8::appstreamlibtasn1-debuginfobefore 0:4.13-6.el8_100:4.13-6.el8_10
Red Hat:enterprise_linux:8::appstreamlibtasn1-debugsourcebefore 0:4.13-6.el8_100:4.13-6.el8_10
Red Hat:enterprise_linux:8::appstreamlibtasn1-develbefore 0:4.13-6.el8_100:4.13-6.el8_10

+21

Same product

gnu: all records

Other highest-scoring records for the same primary product.

  • CVE-2021-46848GNU Libtasn1 before 4.19.0 has an ETYPE_OK off-by-one array size check that affects asn1_encode_simple_der.
    37Monitor
  • CVE-2017-6891Two errors in the "asn1_find_node()" function (lib/parser_aux.c) within GnuTLS libtasn1 version 4.10 can be exploited to cause a stacked-bas
    37Monitor
  • CVE-2016-4008The _asn1_extract_der_octet function in lib/decoding.c in GNU Libtasn1 before 4.8, when used without the ASN1_DECODE_FLAG_STRICT_DER flag, a
    32Monitor
  • CVE-2018-6003An issue was discovered in the _asn1_decode_simple_ber function in decoding.c in GNU Libtasn1 before 4.13.
    31Monitor
  • CVE-2017-10790The _asn1_check_identifier function in GNU Libtasn1 through 4.12 causes a NULL pointer dereference and crash when reading crafted input that
    31Monitor
  • CVE-2015-3622The _asn1_extract_der_octet function in lib/decoding.c in GNU Libtasn1 before 4.5 allows remote attackers to cause a denial of service (out-
    27Monitor

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 gnutls 3.8.3-8 on Azure Linux 3.03.8.3-8 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 libtasn1 4.19.0-2 on Azure Linux 3.04.19.0-3 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 libtasn1 4.19.0-3 on Azure Linux 3.04.19.0-3 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 gnutls 3.7.11-6 on CBL Mariner 2.03.7.11-6 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 libtasn1 4.19.0-2 on CBL Mariner 2.04.19.0-3 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 libtasn1 4.19.0-3 on CBL Mariner 2.04.19.0-3 · CBL-Mariner ReleasesMicrosoft (MSRC)
almalinux:libtasn14.20.0-5.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:libtasn1-devel4.20.0-5.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:libtasn1-tools4.20.0-5.el10_2 · AlmaLinux:10Package registry (OSV)
alpine:libtasn14.21.0-r0 · Alpine:v3.20Package registry (OSV)
debian:libtasn1-64.20.0-2+deb13u1 · Debian:13Package registry (OSV)
opensuse:libtasn14.13-150000.4.14.1 · openSUSE:Leap 15.6Package registry (OSV)
red hat:libtasn10:4.20.0-5.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:libtasn1-debuginfo0:4.20.0-5.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:libtasn1-debugsource0:4.20.0-5.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:libtasn1-devel0:4.20.0-5.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:libtasn1-tools0:4.20.0-5.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:libtasn1-tools-debuginfo0:4.20.0-5.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
rocky linux:libtasn10:4.20.0-5.el10_2 · Rocky Linux:10Package registry (OSV)
suse:libtasn14.13-150000.4.14.1 · SUSE:Linux Enterprise Micro 5.3Package registry (OSV)
suse:libtasn14.9-3.19.1 · SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5Package 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.

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.

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.

No nightly-computed relations.

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
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-787 · Out-of-bounds Write

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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

  1. Fix✗ → ✓

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